SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 221 19 Gulf of Mexico

(1) The Gulf of Mexico coast of the United States, from sand, which rise to a crest with groves of trees on the Key West, FL, to the Rio Grande, is low and mostly sandy, inner slopes. Sand and shell ridges, sometimes several presenting no marked natural features to the mariner feet above the general level, are found throughout the approaching from seaward; shoal water generally extends marshes. These ridges, called Chenieres because of the well offshore. The principal points and harbor entrances oak groves usually found growing on them, are former are marked by lights, which are the chief guides for barrier beaches; good examples are Grande Chenier and approaching or standing along the coast. Pecan Island. In addition to the cheniere, three other marsh (2) From the south shore of the Florida mainland, the features are defined. Small solitary hills are called either Florida Keys and Florida Reefs extend for about 134 islands or mounds depending on their height above the miles in the southwest curve to Sand Key Light and about level of the surrounding marsh. Islands are greater than 25 58 miles in a west direction to Loggerhead Key. These feet while mounds are less. A bayou is a drainage stream keys and reefs are of sand, shell and coral formation. The for a swamp area or an auxiliary outlet for a river. They reefs have frequent shoal patches. The keys are generally flow either to the Gulf of Mexico or a large lake, rarely low and covered with mangrove. Together, they form the into a river or other bayou. The depth of water is nearly north boundary of the Straits of Florida. Toward the always sufficient for river-craft navigation. The current, west end are several openings between the keys offering except after a heavy rainfall, is very sluggish but often passage from the straits into the Gulf. may be reversed by a change in the direction of the wind. (3) The southwest extremity of the Florida mainland is The highest land is found immediately adjacent to the part of the Everglades National Park and Big Cypress bayous in the form of natural levees; as a rule, the larger Swamp. Much of these areas is under water throughout the bayou the higher its levee. the year and is nearly all covered during the rainy summer (7) From Galveston Entrance to the mouth of the Rio season. Fronting the swampy areas are the Ten Thousand Grande the coast is a barrier beach of long narrow islands Islands, a group of low mangrove-covered islands divided and peninsulas, which are generally low and sandy, by tidal channels. North of the Ten Thousand Islands the with but few distinguishing marks, enclosing a chain of coast is low, sandy and generally backed by pine forests shallow bays or lagoons, some of considerable size. The and Hammocks. These hammocks are a jungle of tropical passes between the islands, except where improvements trees, mostly hardwood, which appear as an impenetrable have been made by constructing jetties and dredging, are green wall. narrow and cannot be distinguished from offshore.

(4) From Cape Romano to Anclote Keys the coast (8) becomes a barrier beach of low islands separated by inlets, State boundaries most of which are small and cannot be distinguished from (9) The boundary between Florida and Alabama follows offshore. Between Anclote Keys and St. James Island, the the Perdido River. The Alabama-Mississippi boundary west side of Apalachee Bay, the coast is low and marshy follows a marked line cutting across the east end of for 1 to 2 miles inland then backed by pine forests. The Petit Bois Island, through Grande Batture Islands. Pearl shoreline is broken by a number of unimportant rivers and River, from its most east junction with Lake Borgne, creeks. forms the boundary between Mississippi and Louisiana. (5) West of St. James Island to the South Pass of the Sabine Pass, Lake and River form the boundary between Mississippi River, the coast is mostly a barrier beach Louisiana and Texas. of low, wooded sand islands. The general drift of these (10) islands is to the west, which causes an encroachment upon Disposal sites and dumping grounds the channels between them. Hurricanes and heavy gales (11) These areas are rarely mentioned in the Coast Pilot will sometimes change the shape of these islands, and in but are shown on the nautical charts. (See Dump Sites and some cases they have washed away leaving only shoals. Dumping Grounds, chapter 1, and charts for limits.) (6) Westward of the Delta to Galveston Entrance, the coast is a wide fringe of flat and generally treeless coastal (12) marsh containing close growths of sedge, grass and Aids to Navigation rushes with several deep indentations or bays separated (13) Lights and buoys are the principal guides to mark from the Gulf by chains of long narrow islands and many the approaches to the important harbors. Many of the shallow saltwater lakes and lagoons. The islands and light stations have sound signals, particularly those in marshes are fringed with barrier beaches, mostly of fine the vicinity of the larger ports. Many of the coastal and U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 222

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harbor buoys are equipped with radar reflectors, which notification of arrivals, departures, hazardous conditions greatly increase the range at which the buoys may be and certain dangerous cargoes to the Captain of the Port.)

detected on the radarscope. Most of the critical dangers (20) are marked. (See the Light List for a complete description Harbor entrances of navigational aids.) (21) The entrances to most of the harbors along the Gulf (14) Coast are obstructed by shifting sandbars. The more Radar important entrances have been improved by dredging (15) Radar is an important aid to navigation in this and in some cases by construction of jetties. On many of area, particularly in detecting other traffic and offshore the bars the buoys are moved from time to time to mark oil platforms and in the prevention of collisions during the shifting channels. The best time to enter most of the frequent periods of low visibility. The coast is generally harbors is on a rising tide. low and does not present a good radar target, but many (22) The tidal currents have considerable velocity in most of the coastal buoys are equipped with radar reflectors. of the harbor entrances, and their direction is affected by

(16) the force and direction of the wind. In south gales the sea COLREGS Demarcation Lines breaks on some of the bars. (17) Lines have been established to delineate those waters (23) upon which mariners must comply with the International Shipping safety fairways Regulations for Preventing Collisions at Sea, 1972 (72 (24) A system of shipping safety fairways has been COLREGS) and those waters upon which mariners must established along the Gulf Coast to provide safe lanes comply with the Inland Navigational Rules Act of 1980 for shipping that are free of oil well structures. Vessels (Inland Rules). The waters inside of the lines are Inland should approach the harbor entrances and proceed Rules Waters, and the waters outside of the lines are coastwise between the ports within these fairways but COLREGS Waters. (See 33 CFR Part 80, chapter 2, should exercise due caution at all times as the lanes for specific lines of demarcation.) are unmarked. (See 33 CFR 166.100 through 166.200,

(18) chapter 2, for references to the charts showing the limits Ports and waterways safety of the fairways, and the regulations governing them.) (19) (See 33 CFR Part 160, chapter 2, for regulations governing vessel operations and requirements for SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 223 19

(25) (42) Anchorages Tropical waters (26) Fairway anchorages have been established off the (43) The most remarkable feature is the exceeding entrances to some of the ports; these areas are generally clearness of the sea water, enabling the bottom to be seen free of oil well structures. (See 33 CFR 166.100 through from aloft at considerable depths and at some distance. 166.200, chapter 2, for references to the charts showing The navigation of the banks is consequently conducted the limits of the anchorages, and regulations governing almost entirely by the eye, but care must be taken not to them.) Other anchorages have been established along the run with the sun ahead of the vessel as that prevents the Gulf Coast, bays, sounds and rivers. (See 33 CFR Part banks from being seen. 110, chapter 2, for limits and regulations.) (44) The charts indicate clearly the positions of the many

(27) shoal heads, but considerable experience is required in Lightering Zones identifying the patches by the color of the water. Small (28) Lightering zones and prohibited-from-lightering clouds, moving slowly and known to the pilots as flyers, zones have been established in the Gulf of Mexico as are apt to deceive the inexperienced, their reflection on follows These areas will be shown on the applicable the surface of the sea over the clear white sandy bottom nautical chart. having every appearance of rocky shoals. It is prudent to (30) Southtex-lightering Zone, centered about 150 miles, avoid a dark spot. 105° from Aransas Pass; (45) Bank blink is a phenomenon in tropical waters (31) Gulfmex No. 2-lightering Zone, centered about 120 described as a bright reflected light hanging over the miles, 210° from Head of Passes, Mississippi River; clear white sandbanks, serving to point them out from (32) Offshore Pascagoula No. 2-lightering Zone, centered a considerable distance. From experience, it has been about 130 miles, 150° from Pascagoula; found to be untrustworthy, however, and should not (33) South Sabine Point-lightering Zone, centered about be depended on in place of a lookout aloft. Soundings, 95 miles, 160° from Sabine Pass; the reckoning and especially the latitude, should be (34) Claypile-prohibited-from-lightering Zone, centered unremittingly checked. about 90 miles, 160° from Galveston Bay entrance; (46) (35) Flower Garden-prohibited-from-lightering Zone, Marine protected areas centered about 120 miles, 150° from Sabine Pass; (47) Marine protected areas (MPAs) are special places (36) Ewing-prohibited-from-lightering Zone, centered in ocean, coastal and estuarine ecosystems where vital about 100 miles, 240° from Head of Passes, Mississippi natural and cultural resources are given greater protection River (See 33 CFR Parts 156.300 through 156.330, than in surrounding waters. MPAs have been used in the chapter 2, for limits and regulations.). U.S. for more than a century. Currently, there are over

(37) 1,600 MPAs in U.S. marine waters and the Great Lakes, Vessel Traffic Services (VTS) with levels of protection ranging from a few “no-take” (38) Vessel Traffic Services (VTS) or Vessel Traffic areas that prohibit all extractive uses to the more common Information Services (VTIS) have been established multiple use areas in which a variety of consumptive and in Calcasieu Ship Channel (Lake Charles VTS), in the non-consumptive uses are allowed and often encouraged. Houston-Galveston Bay area (Houston-Galveston VTS) (48) MPAs are managed by dozens of federal, state, tribal and in the Atchafalaya River at Morgan City, LA (Berwick and local authorities. For detailed information on MPA Bay VTS). The services have been established to prevent locations, types, purposes and legal restrictions, visit collisions and groundings and to protect the navigable www.marineprotectedareas.noaa.gov. waters from environmental harm. (49) There are over 300 MPAs in this Coast Pilot Region (39) The Vessel Traffic Services for Berwick Bay and from Texas to the west coast of Florida, and Puerto Rico the Houston-Galveston Bay area provide for Vessel and Virgin Islands. Most of these are small, near-shore Traffic Centers (VTC) that may regulate the routing and MPAs managed by state agencies. Several large MPAs movement of vessels by radar surveillance, movement have been established in federal waters to restore fisheries reports of vessels, VHF-FM radio communications and protect habitat. Other federal MPAs in the region and specific reporting points. The services consist of include National Marine Sanctuaries, such as Flower precautionary areas and reporting points. Garden Banks; National Parks, such as Gulf Islands (40) The Lake Charles Vessel Traffic Information Service National Seashore in Texas; and National Wildlife (VTIS) consists of reporting points and special conditions Refuges, such as the Breton National Wildlife Refuge in to be observed within the VTIS area. Louisiana. (41) Lake Charles Vessel Traffic Service is voluntary, (50) and Houston-Galveston and Berwick Bay Vessel Traffic Area to Be Avoided Services are mandatory. (See chapters 8, 9, and 10 for (51) The Florida Keys Particularly Sensitive Sea Area details of the Vessel Traffic Services and Vessel Traffic (PSSA) is an International Maritime Organization (IMO) Information Services.) designated zone that encircles the sea area around all of U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 224

the Florida Keys. The PSSA includes the entire Florida Area Surrounding the Marquesas Keys Keys National Marine Sanctuary as well as Biscayne Point Latitude Longitude National Park at the northeastern end of the Keys. The 38 24°36.15'N. 81°51.78'W. PSSA is bounded by a line connecting the following points: 39 24°34.40'N. 81°50.60'W. 40 24°33.44'N. 81°49.73'W. (52) 41 24°31.20'N. 81°52.10'W. In The Vicinity of the Florida Keys 42 24°28.70'N. 81°56.80'W. Point Latitude Longitude 43 24°26.60'N. 81°59.55'W. 1 25°45.00'N. 80°06.10'W. 2 25°38.70'N. 80°02.70'W. (55) 3 25°22.00'N. 80°03.00'W. Area Surrounding the Dry Tortugas Islands 4 25°06.38'N. 80°10.48'W. 44 24°32.00'N. 82°53.50'W. 5 24°56.37'N. 80°19.26'W. 45 24°32.00'N. 83°00.05'W. 6 24°37.90'N. 81°47.30'W. 46 24°39.70'N. 83°00.05'W. 7 24°29.20'N. 81°17.30'W. 47 24°45.60'N. 82°54.40'W. 8 24°22.30'N. 81°43.17'W. 48 24°45.60'N. 82°47.20'W. 9 24°28.00'N. 81°43.17'W. 49 24°42.80'N. 82°43.90'W. 10 24°28.70'N. 81°43.50'W. 50 24°39.50'N. 82°43.90'W. 11 24°29.80'N. 81°43.17'W. 51 24°35.60'N. 82°46.40'W. 12 24°33.10'N. 81°35.15'W. 52 24°32.00'N. 82°53.50'W. 13 24°33.60'N. 81°26.00'W. 14 24°38.20'N. 81°07.00'W. (56) 15 24°43.20'N. 80°53.20'W. Dangers 16 24°46.10'N. 80°46.15'W. (57) Danger zones and restricted areas, extending as 17 24°51.10'N. 80°37.10'W. much as 100 miles offshore, are located in the Gulf of 18 24°57.50'N. 80°27.50'W. Mexico from Key West to the Rio Grande. (See 33 CFR 19 25°09.90'N. 80°16.20'W. Parts 162 and 334, chapter 2, for limits and regulations.) 20 25°24.00'N. 80°09.10'W. (58) Fish havens, some marked by privately maintained 21 25°31.50'N. 80°07.00'W. buoys, are numerous along the coast of the Gulf of 22 25°39.70'N. 80°06.85'W. Mexico. Navigators should be cautious about passing 23 25°45.00'N. 80°06.10'W. over fish havens or anchoring in their vicinity. (59) (53) Wrecks In the Vicinity of Key West Harbor (60) Numerous wrecks, submerged and showing above 24 24°27.95'N. 81°48.65'W. water, in the bays, sounds and rivers and along the coast of the Gulf of Mexico are obstructions to navigation. A 25 24°23.00'N. 81°53.50'W. careful check should be made of the chart to ensure that 26 24°26.60'N. 81°58.50'W. dangerous wrecks are not along the routes selected. 27 24°27.75'N. 81°55.70'W. (61) Periodically, District Engineer, New Orleans Corps 28 24°29.35'N. 81°53.40'W. of Engineers, publishes in a navigation bulletin the 29 24°29.35'N. 81°50.00'W. locations of obstructions affecting navigation in navigable 30 24°27.95'N. 81°48.65'W. waterways within the State of Louisiana that are within the New Orleans district boundaries. (See Appendix A (54) for extent of the New Orleans District.) This list includes Area Surrounding the Marquesas Keys obstructions in the Gulf within the 3-mile limit. Point Latitude Longitude (62) 31 24°26.60'N. 81°59.55'W. Oil Well structures 32 24°23.00'N. 82°03.50'W. (63) Numerous submerged wells and oil well structures 33 24°23.60'N. 82°27.80'W. (platforms), including appurtenances thereto, such as mooring piles, anchor and mooring buoys, pipes 34 24°34.50'N. 82°37.50'W. and stakes, exist in the Gulf of Mexico off the coasts 35 24°43.00'N. 82°26.50'W. of Mississippi, Louisiana and Texas. The heaviest 36 24°38.31'N. 81°54.06'W. concentration of these obstructions, however, is found 37 24°37.91'N. 81°53.40'W. between the Mississippi River Delta and Galveston Bay, extending as much as 70 miles offshore. SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 225 19

(64) In general, the oil well structures (platforms) in the is not mandatory, mariners should take advantage of the Gulf are marked at night as follows: safer passageways made available. (65) Structures outside the 5-fathom curve show quick (76) Information concerning seismographic operations flashing white lights visible from all directions ata is not published in Notice to Mariners unless such distance of at least 5 miles; more than one light may be operations will create a menace to navigation in waters displayed. Sound signals are sounded from the structures used by general navigation. Where seismographic when visibility is less than 5 miles; signal consists of a operations are being conducted, casings (pipes), buoys, horn sounding one 2-second blast every 20 seconds. stakes and detectors are installed. Pipes are marked with (66) Structures between the 2-fathom and 5-fathom flags by day and fixed red lights by night, buoys are curves show quick flashing white lights visible from all colored international orange and white horizontal bands, directions at a distance of at least 3 miles. Sound signals and stakes are marked with flags.

are sounded from the structures when visibility is less (77) than 3 miles. Pipelaying barges (67) Structures along the coast in less than 2 fathoms and (78) With the increased number of pipeline-laying within the bays and sounds show either quick flashing operations, operators of all types of vessels should be white or red lights visible from all directions at a distance aware of the dangers of passing close aboard, close of at least 1 mile. Normally these structures are not ahead or close astern of a jetbarge or pipelaying barge. equipped with sound signals. Pipelaying barges and jetbarges usually move at 0.5 knot (68) Structures on or adjacent to the edges of navigable or less and have anchors that extend out about 3,500 to channels and fairways, regardless of location, may be 5,000 feet in all directions and that may be marked by required to display lights and sound signals for the safety lighted anchor buoys. The exposed pipeline behind the of navigation. pipelaying barge and the area in the vicinity of anchors (69) Associated structures within 100 yards of the main are hazardous to navigation and should be avoided. The structures, regardless of location, are not normally lighted pipeline and anchor cables also represent a submerged but are marked with red or white retro-reflective material. hazard to navigation. It is suggested, if safe navigation Mariners are cautioned that uncharted submerged permits, for all types of vessels to pass well ahead of pipelines and cables may exist in the vicinity of these the pipelaying barge or well astern of the jetbarge. structures or between such structures and the shore. The pipelaying barge, jetbarge and attending vessels (70) During construction of a well or during drilling may be contacted on VHF-FM channel 16 for passage operations and until such time as the platform is capable instructions. of supporting the required aids, fixed white lights on the (79) attending vessel or drilling rig may be shown in lieu of Drawbridges the required quick flashing white lights on the structure. (80) The general regulations that apply to all drawbridges The attending vessel’s foghorn may also be used as a are given in 33 CFR 117.1 through 117.49, chapter 2, substitute. and the specific regulations that apply only to certain (71) Submerged wells may or may not be marked drawbridges are given in 33 CFR Part 117, Subpart B, depending on their location and depth of water over them. chapter 2. Where these regulations apply, references to (72) All obstruction lights and sound signals used to them are made in the Coast Pilot under the name of the mark the various structures are operated as privately bridge or the waterway over which the bridge crosses. maintained aids to navigation. The detailed regulations (81) The drawbridge opening signals (see 33 CFR 117.15, for the marking of offshore structures are contained in chapter 2) have been standardized for most drawbridges 33 CFR 67 (not carried in Coast Pilot 5.) within the United States. The opening signals for those (73) Information concerning the establishment, change few bridges that are nonstandard are given in the specific or discontinuance of offshore oil well structures and their drawbridge regulations. The specific regulations also appurtenances are published in Notice to Mariners with address matters such as restricted operating hours and the exception of those inside the outer shoreline. required advance notice for openings. (74) All structures in the Gulf of Mexico are shown on the (82) The mariner should be acquainted with the general latest issues of the 1:80,000 and/or larger scale nautical and specific regulations for drawbridges over waterways charts covering the area. A warning note in lieu of the to be transited. individual obstructions is shown on some charts. Some Gulf charts show oil well structures only when they are (83) offshore of the indicated purple limits of the 1:80,000 Routes scale charts. (84) On the east side of the Gulf of Mexico, for a distance (75) Mariners are advised to use the Shipping Safety of possibly 100 miles outside the 100-fathom curve, Fairways that have been established in the Gulf of southeast currents prevail and velocities as high as 2.5 Mexico. These fairways provide shipping lanes free of knots have been reported. The Gulf Stream investigations oil drilling structures. Although the use of these fairways indicated that the strongest current into the Straits of Florida is found near the 1,000-fathom curve west of U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 226

Dry Tortugas and that velocities of 1.5 to 2 knots are modify conditions, and their effects must be taken into frequent in that locality. Approaching Dry Tortugas from account.

the Gulf should, therefore, be regarded as a difficult run, (90) as a vessel will overrun her log, and observations are the Inside navigation principal guide; currents may be expected at all times, (91) Navigation on the waterways covered by this volume but variations occur both in direction and velocity, due requires a knowledge of the channel conditions and other to the season of the year and the winds. Approaching factors restricting navigation. General items of interest to Dry Tortugas a vessel must take care to stand outside the the vessel operator are indicated in the paragraphs that Area To Be Avoided Off the Coast of Florida (ATBAOCF, follow; details are given in the text. indexed as such, this chapter). (92) Special regulations governing the use, administration (85) Approaching the passage west of Rebecca Shoal and navigation of floodgates and locks of the Intracoastal from north, a number of vessels have stranded on New Waterway are given in 33 CFR 207.185 and 207.187, Ground, indicating an east set. chapter 2. (86) Junction point for deep-draft vessels bound to or (93) from Gulf Coast ports is Straits of Florida (24°25'N., Manmade canals 83°00'W.), which is 14 miles south-southwest of Dry (94) In addition to the numerous bayous and natural Tortugas Light. canals, thousands of manmade canals have been dredged (87) From the Straits of Florida to Cape Hatteras vessels in the wetlands along the Gulf coast. While the original follow the Gulf Stream and pass about 14 miles south of purpose of many of these canals was for private access Rebecca Shoal Light. Vessels then parallel the Florida to pipelines and well locations or for other mineral- Reefs, taking care to stand outside the ATBAOCF. See related activities, some are used by boaters. These canals Area To Be Avoided Off the Coast of Florida (indexed and bayous contain numerous obstructions including as such), this chapter. Fowey Rocks Light is passed barriers, pipes, pilings and construction debris. Some at a distance of 10 to 12 miles and Jupiter Inlet Light of these structures are permanently maintained and 15 miles. The velocity of the current varies greatly in have been suitably marked or lighted by their owners. different localities and is also subject to sudden changes, Many others appear and disappear without notice and due to wind, differences in barometric pressure, and the are uncharted, unlighted and unmarked. Even on the like, so that no fixed hourly rate of drift can be given. marked structures, mariners cannot rely on the markings Frequently high velocities will be carried between certain always being maintained in good condition because of points and suddenly dropping off between others. The vandalism or weather damage. Therefore, all persons position should, therefore, be checked whenever possible using canals and bayous must anticipate the hazards by bearings. The ship speed plus supposed rate of current posed by these obstructions and navigate with extreme should not be assumed to fix the position. The greatest caution, especially at night and during periods of reduced velocity will be found between Carysfort Reef and Jupiter visibility. Inlet, ranging from 2 to 4.5 knots. (88) During the winter months when northers are (95) frequent, it is well for westbound vessels to keep a Bends and curves little north of the 295° course from Dry Tortugas to (96) In the Intracoastal and adjoining waterways there are Heald Bank Lighted Whistle Buoy but go south of it in many sharp bends that are dangerous to vessels meeting passing. In either direction, verify position as often as or passing. On approaching a bend, a vessel should possible, because of the varying conditions of the current. reduce speed sufficiently to be able to stop within half For 300 miles before reaching Heald Bank, westbound the distance to a ship coming from the opposite direction. craft frequently overrun, especially during the winter Under no circumstances should a vessel attempt to months, and eastbound vessels overrun the last 300 miles overtake and pass another at a bend. Even with sufficient before reaching Dry Tortugas. Depend upon soundings view of the channel ahead and after proper exchange westbound but upon observations eastbound. and understanding of signals, the overtaken vessel may (89) Currents along the course from Dry Tortugas to suddenly sheer from current action. This is even more Galveston are subject to great variability. However, pronounced with larger vessels and tows. observations have shown that a 0.5-knot southeast (97) current may be expected for 200 miles after leaving Dry Crosscurrents Tortugas. For the next 100 miles the current generally (98) Where two streams cross, the current will have a sets east at 0.5 knot. For the next 200 miles the set is greater velocity in the deeper channel. This is noticeable about north-northeast at 0.2 knot. For nearly 200 miles along the Intracoastal Waterway where it follows a dredged before reaching Galveston the set is approximately canal cutting across a winding stream. Crosscurrents will west-northwest at 0.2 knot. It is emphasized that this also be noticed where either an inlet from the ocean or a approximates the long-term mean current pattern and that drainage canal or a river enter the waterway. it may not be experienced on any particular voyage. (See (99) Crosscurrents are especially strong along the Loop Current, this chapter.) Winds and storms frequently Intracoastal Waterway in San Carlos Bay, The SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 227 19

Rigolets-New Orleans Cut, Chef Menteur Pass, Vermilion shocks of the heavy gusts. If the banks are lined only with River Cutoff and Brazos and Colorado Rivers. small trees or large shrubs, use clumps of them within

(100) each hawser loop. Keep clear of any tall pines as they Spoil banks generally have shallow roots and are more apt to be blown (101) Nature quickly covers her scars. This is true of the down. spoil banks made by dredging. When awash, these banks (109) are often covered by grass, bushes and sometimes fairly Manatees large trees. (110) The West Indian manatee is a herbivorous marine (102) Water hyacinth is a floating freshwater plantwhich mammal that is protected at the federal level by the Marine infests numerous streams tributary to the South Atlantic Mammal Protection Act of 1972 and the Endangered and Gulf Coasts. It has bright green leaves and a purple Species Act of 1973. These acts make it illegal to harass, flower. It propagates from seeds and suckers, spreads hunt, capture or kill any marine mammal, including all quickly in most localities and may cause complete dolphins, whales and manatees. The manatee is a large suspension of navigation if not removed. The hyacinths (approximately 8 to 10 feet in total length) and slow- form in mats or jams and float around driven by the wind moving marine mammal with a torpedo-like body and or current. In open water these mats often resemble small a paddle-shaped tail. These animals mainly inhabit the islands. At times some of the bays and tributaries may estuarine and inland waters of Florida, although they have be changed in appearance due to hyacinth jams. Where been sighted in the Atlantic Ocean and Gulf of Mexico the water is apt to be brackish, an attempt can be made and have been seen as far north as Massachusetts and to force a boat through the mat. In doing so, however, as far west as Texas. Due to their sensitivity to colder care should be taken that any logs that might be floating temperatures, in the winter manatees move from cooler in the weeds are not struck with force enough to damage waters and congregate, sometimes in large numbers, in the hull. Snakes may also be found on the hyacinth mats. warmer rivers and springs, streams and canals and near The work of removing this growth is undertaken by the the cooling water discharge outlets of power plants and various Corps of Engineers districts and the State of other industrial sources. During the spring and autumn Florida by the processes of spraying and cutting and the months, many manatees undertake extensive migrations use of booms. along the Atlantic and Gulf Coasts. Manatee distribution

(103) in the warmer months of the year is typically more Mangrove widespread. (111) (104) Three distinct types of mangrove are found in the Manatees need to surface regularly to breathe, south section of this area. Yellow or white mangrove is approximately every 2 to 10 minutes, but are capable found principally on the sand flats in front of the fast land. of holding their breath for up to 20 minutes. Calves are Red mangrove is rooted in water most of the time. Black approximately 3 feet in length at birth and stay with the mangrove grows on sand ridges and higher ground which mother for a period of up to 2 years. During this time, they cover only at very high water or storm tides. The black nurse regularly from the mother and take more frequent mangrove sometimes grows to a height of 50 to 60 feet. breaths than a larger adult. This mother-calf bond is very Along the coast from Cape Sable to Everglades City, most important and critical to the survival of the calf; it is mangroves grow from 25 to 50 feet high with some stands very important that the mother and calf do not become of red mangroves reaching above 60 feet. Along the coast separated. Manatees are typically solitary in nature, found of Florida Bay, the red and black mangroves generally do as a cow-calf pair, or found in small groups. However, not exceed a height of about 26 feet. when a female is in estrus, she may be accompanied by large numbers of males, typically referred to as a mating (105) herd. Stumps and sunken logs (112) Statewide aerial surveys (synoptic surveys) are (106) Reports are frequently made that vessels have struck conducted following significant cold weather to provide shoals or rocks in rivers that have later proved to be stumps a minimum population estimate for manatees in Florida or sunken logs. Mariners are warned against navigating waters. In January 2009, the synoptic survey resulted too close to the banks of streams where submerged in a total count of 3,802 manatees on both the east and stumps are known or may be expected to exist. west coasts of Florida. This is a minimum count, and (107) it is reasonable to assume that some manatees were not Hurricane moorings detected during the surveys. Manatees are quite docile (108) On receiving advisory notice of a tropical disturbance and have no natural enemies but are an endangered small boats should seek shelter in a small winding stream species, mostly due to collisions with boats, which have whose banks are lined with trees, preferably cedar or caused as many as 95 deaths per year. Watercraft-related mangrove. Moor with bow and stern lines fastened to mortality may result from injuries caused by the propeller the lower branches; if possible snug up with good chafing and/or impact from a collision with a vessel. As such, gear. The knees of the trees will act as fenders, and the manatee protection speed zones (ranging from no entry branches, having more give than the trunks, will ease the U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 228

zones to 30 miles per hour zones) exist around the State is about 14 feet, the water being highest in the spring of Florida to provide additional protection in areas of months and lowest during the autumn and early part of the high manatee use and high watercraft-related mortality. winter. An extreme fluctuation of 21 feet in the river level (113) The Florida Manatee Sanctuary Act authorizes the at this city has been reported. (See Tidal information, Florida Fish and Wildlife Conservation Commission including real-time water levels, tide predictions and tidal (FWC) and, in some cases, local governments, to regulate current predictions is available at tidesandcurrents.noaa. motorboat speed and operation in areas frequently used gov.)

by manatees. The regulated zones are marked by large (120) reflective signs or buoys. In these zones, boat operators Currents must operate their vessels at or below the established (121) Under normal conditions, at all seasons of the year, limits, and no person may intentionally or negligently the great volume of water passing north through Yucatan annoy, molest, harass, disturb, collide with, injure or Channel into the Gulf of Mexico spreads out in various harm manatees. Maps of the state zones are available at directions. Surface flows set: west across Campeche myfwc.com. Questions about the state regulations should Bank, the Gulf of Campeche, and the Sigsbee Deep; be directed to the FWC Imperiled Species Management northwest toward Galveston and Port Arthur; north- Section, 620 South Meridian Street, Tallahassee, FL northwest toward the Mississippi Passes; and east into 32399. Regulated zones within the area covered by this the Straits of Florida. Coast Pilot are in Faka Union Bay, River and Canal; in the (122) A straight line drawn from Buenavista Key, Western Caloosahatchee River from San Carlos Bay to the Edison Cuba, to the Mississippi Passes forms an approximate Memorial Bridge (U.S. 41); in Orange River and at its boundary between movements having different confluence with Caloosahatchee River; in Withlacoochee directions. West of this line the drift is generally north or River; in the approach to Alafia River from the main west, while east of it the drift is east or southeast toward channel through Hillsborough Bay; in the Homosassa the Straits of Florida. River; and in Kings Bay on the Crystal River. (123) There are north flows along the west side of the (114) Gulf between Tampico and Corpus Christi in the vicinity Tides of the 100-fathom and 1,000-fathom curves, north of (115) Periodic tides in the Gulf of Mexico usually are small the Sigsbee Deep between the 2,000-fathom and the and may, therefore, be greatly modified and sometimes 100-fathom curves, and along the west coast of Florida. obliterated by fluctuations in the water surface due to (124) In general, the surface circulation is the same at all winds or other meteorological conditions. seasons. There is, however, some seasonal change in (116) At Key West the mean range of tide is 1.3 feet. velocity, the flow being generally stronger in spring and Extreme variations in the level from 1.5 feet below the summer than in the autumn and winter. plane of reference to 4 feet above may occur in this (125) The current near the Florida Keys is variable and locality. uncertain. (117) Along the west coast of the peninsula of Florida from (126) Tidal currents are generally weak in the open Gulf, Cape Sable to Apalachee Bay, the mean range varies from but they are strong at times near shore, in the vicinities 0.5 to 3.6 feet. Extreme tides from 3 feet below to 6 feet of shoals, and in the entrances to harbors. See the Tidal above the plane of reference have been observed on this Current Predictions at tidesandcurrents.noaa.gov for coast. more information. Links to a user guide for this service (118) Along the north shore of the Gulf of Mexico from can be found in chapter 1 of this book. St. George Sound to the Rio Grande the tide is generally diurnal and the range is less than 3 feet, but fluctuations (127) The Gulf Stream System is the most famous of due to the wind from 3.5 feet below to 4 feet above the the principal ocean currents. The name was first used plane of reference are not uncommon. During the severe by Benjamin Franklin in 1769. In general, as the swift storms that occasionally visit this region, high waters current of the Gulf Stream issues into the sea through from 10 to 12 feet above the plane of reference have Straits of Florida, its waters are characterized by a deep been reported at Galveston, TX, and 12.7 feet has been blue color, high salinity, high temperature in the upper observed at Port O’Connor, TX. stratum and absence of phosphorescence. Except near (119) The periodic or astronomical tide, small at the mouth shoals where waves may stir up bottom sediments, Gulf of the Mississippi River, gradually diminishes as it ascends Stream water is very clear, enabling visual penetration the river until it finally becomes completely masked by to unusually great depths. At its junction with coastal the larger fluctuations resulting from meteorological seawater, the edges may frequently be recognized in conditions. At New Orleans the diurnal range of the tide moderate weather by ripples, as well as by the difference during low-river stages averages about 0.8 foot. There is in color. Northward, in the cooler regions, the evaporation no periodic tide at high-river stages. There is, however, from its surface, when the temperature of the air is lower a large fluctuation in the level due to the condition of than that of the water, is apparent as “sea smoke.” In the river. The mean annual fluctuation at New Orleans addition, the stream may carry with it some Gulf weed SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 229 19

(Sargassum), which is olive brown, branched seaweed about 1.5 miles per day west after formation in the region with berrylike air vessels. between the stream and the continental shelf to about (128) The upstream extent of the Gulf Stream System can 70°W. From 70°W the rings generally move southwest be traced to the Yucatan Strait where a well-established along the continental shelf and eventually are absorbed current enters the Gulf of Mexico. The current in the Gulf into the stream near Cape Hatteras. Many warm rings of Mexico is called the Loop Current. The position of the are absorbed by the stream well before they reach Cape Loop Current is quite variable, but there is some evidence Hatteras. About 20 warm rings are formed each year and of a cyclical pattern of about 290 days. The Loop Current average about a 20-week life cycle. Cold rings average begins with a short flow pattern protruding into the Gulf about 60 miles in diameter and are found south of the of Mexico, then it slowly builds up, gradually protruding stream in the Sargasso water region. Cold rings rotate in northward and westward into the Gulf and reaching as far a counterclockwise direction with a maximum flow of as 28°N and 90°W before shedding a large warm ring. about 1.6 knots located 2/3-3/4 from the center. Cold ring The remaining Loop Current has a shortened flow path velocities can be significantly higher than 1.6 knots. Cold and begins the process anew. The large detached warm rings tend to move about 1.5 miles per day southwest after ring will drift west about 1.5 miles per day to southwest formation and are eventually absorbed back into the Gulf into the western Gulf of Mexico where it will eventually Stream. About 20 cold rings are formed each year and dissipate. Gulf of Mexico warm rings average about 120 average about a 1.5 year life cycle. miles in diameter. The warm ring has a clockwise flow (133) East of the Grand Banks of Newfoundland, the with a maximum current close inside its periphery of 0.5 whole surface is slowly driven east and northeast by to 1.5 knots. the prevailing west winds to the coastal waters of (129) After entering the Straits of Florida between Cuba northwestern Europe. For distinction, this broad and and the Florida Keys, the Gulf Stream System’s path variable wind-driven surface movement is sometimes becomes much more stable. The major variation of the referred to as the North Atlantic Drift. current from off Key West to off Little Bahama Bank (134) On its west or inner side, the Gulf Stream is appears to be a meandering of the axis of the current separated from the coastal waters by a zone of rapidly within the narrow confines of the Straits. The current falling temperature, to which the term north wall (west within the Straits and slightly to the north is frequently wall from Georgia south) has been applied. The abrupt referred to as the Florida Current. change in the temperature of the waters separated by the (130) Shortly after emerging from the Straits of Florida, north wall (west wall) is frequently very striking and is the Gulf Stream is joined by the Antilles Current, a definite indication of the edge of the stream. It is most which flows northwest along the open ocean side of the clearly marked north of Cape Hatteras but extends, more West Indies. The Antilles Current, like the Gulf Stream, or less well defined, from the Straits of Florida to the carries warm, highly saline waters of clear indigo blue. Grand Banks of Newfoundland. In the vicinity of the The union of the two currents gives rise to a broad and Grand Banks, the north wall represents the dividing line deep current possessing about the same characteristics as between the warm current of the Gulf Stream and the the Florida Current except that the velocity is somewhat cold waters of the Labrador Current, which according reduced. The Gulf Stream from the Florida Straits flows to observations, turns sharply, between 42°–43°N and north, then northeast, paralleling the general trend of the 51°–52°W, and flows parallel to the Gulf Stream. 100-fathom contour up to Cape Hatteras. From 32°N to (135) Throughout the whole stretch from the Florida Keys Cape Hatteras the stream shows some lateral meandering to past Cape Hatteras the stream flows with considerable that does not generally exceed one stream width, or about velocity. Characteristic average surface speed is on the 40 miles. order of 2.5 knots, increasing to about 4.5 knots off Cape (131) Beyond Cape Hatteras the Gulf Stream flows east Florida where the cross-sectional area of the channel is away from the coast and into much deeper water. As least. These values are for the axis of the stream where the it moves into progressively deeper water, the stream current is a maximum, the speed of the stream decreasing is subject to increased meandering, which can have as gradually from the axis as the edges of the stream are large a north-south extent as 270 miles. The wavelike approached. The axis of the stream is estimated to be meanders of the stream propagate east at speeds of about about 3–15 miles seaward of the north wall. Both the 3 to 5 miles per day. These meanders occasionally shed speed and position of the axis of the stream fluctuate from detached current rings or eddies that are found north and day to day, hence description of both position and speed south of the stream and that are respectively warmer and are averages. cooler than the surrounding waters. Rings are generally (136) Crossing the stream at Jupiter or Fowey Rocks, an formed east of 65°W. average allowance of 2.5 knots in a north direction should (132) Warm rings average about 70 miles in diameter and be made for the current. are found north of the stream between it and the continental (137) Crossing the stream from Habana, a fair allowance shelf. Warm rings rotate in a clockwise direction with a for the average current between 100-fathom curves is 1 maximum flow of about 1.6 knots located about 2/3–3/4 knot in an east-northeast direction. from the center of the eddy. Warm rings generally move U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 230

(138) A vessel bound from Cape Hatteras to Habana, or West, FL, to Cape Hatteras, NC. The times of these the Gulf ports, crosses the stream off Cape Hatteras. A broadcasts and their formats vary from station to station, fair allowance to make in crossing the stream is 1 to 1.5 but in general, all give the distance to the inshore edge knots in a northeast direction for a distance of 40 miles of the Stream with reference to a navigational light from the 100-fathom curve. or buoy, the width of the Stream when that is known (139) Earlier systematic observations on the Gulf Stream and the maximum temperature. This information is dealt with the temperature of the water rather than its derived largely from infrared satellite imagery, and it is motion, and the axis was taken to be along the line of unfortunately not available during the warmer summer highest temperature obtained. Later the axis was taken months south of about Jupiter Inlet. (See Appendix A for to mark the line of greatest velocity. Ordinarily it is a list of NOAA Weather Radio stations.) assumed that these two axes coincide, but this is by no (146) For ships in port or with telecopy equipment, an means certain. The thermometer, although it indicates the analysis of the satellite-based Gulf Stream System from limits of the stream in a general way, is therefore only an the central Gulf of Mexico to Cape Hatteras, which approximate guide to the velocity of the currents. includes an estimated location of the maximum current, (140) The lateral boundaries of the current within the is available through the Naval Oceanographic Office Straits of Florida are fairly well fixed, but as the stream at ecowatch.ncddc.noaa.gov/JAG/Navy/data/satellite_ crosses 32°N its east boundary becomes somewhat vague. analysis/gsscofa.gif. On the west side the limits can be defined approximately (147) An analysis of the Gulf Stream System from the since the waters of the stream differ in color, temperature, western Gulf of Mexico to Cape Hatteras (South Panel) salinity and flow from the inshore coastal waters. On and from Cape Hatteras to Nova Scotia (North Panel) is the east, however, the Antilles Current combines with provided the National Weather Service (NWS) Weather the Gulf Stream so that its waters here merge gradually Forecast Offices (WFOs) in their Coastal Waters Forecast with the waters of the open Atlantic. Observations of Synopses. WFO Melbourne, FL; WFO Miami, FL and the National Ocean Survey indicate that, in general, the WFO Key West, FL are found at www.nws.noaa.gov/om/ average position of the inner edge of the Gulf Stream marine/zone/south/stheastmz.htm.

from the Straits of Florida to Cape Hatteras lies inside (148) the 100-fathom curve. Currents (141) At the west end of the Straits of Florida the limits (149) Wind-driven currents are very complicated. of the Gulf Stream are not well defined. Between Fowey Their velocities and directions depend upon a number Rocks and Jupiter Inlet the inner edge lies very close to of factors such as the velocity, direction and duration of the shoreline. the wind; the proximity of the coast and the direction (142) Along the Florida Reefs between Alligator Reef and of the coastline. Generally in the Northern Hemisphere Dry Tortugas the distance of the north edge of the Gulf the wind-driven current sets somewhat to the right of the Stream from the edge of the reefs gradually increases wind, but in coastal waters there are many exceptions to toward the west. Off Alligator Reef it is quite close this general rule, the current often setting to the left of inshore, while off Rebecca Shoal and Dry Tortugas it is the wind, due to the tendency of the current to follow the possibly 15 to 20 miles south of the 100-fathom curve. direction of the coastline or to other local conditions. Between the reefs and the north edge of the Gulf Stream (150) The velocity of the wind current relative to that the currents are ordinarily tidal and are subject at all of the wind also varies with the locality. Wind-current times to considerable modification by local winds and information is available from the Tidal Current prediction barometric conditions. This neutral zone varies in both service at tidesandcurrents.noaa.gov. Links to a user length and breadth; it may extend along the reefs a greater guide for this service can be found in chapter 1 of this or lesser distance than stated, and its width varies as the book. north edge of the Gulf Stream approaches or recedes from (151) the reefs. Weather (143) (152) Climatological tables for coastal locations and Location of the Gulf Stream meteorological tables for coastal ocean areas are found (144) The approximate position of the axis of the Gulf within the appropriate chapters in which they are Stream for various regions is shown on NOS charts: the discussed. The climatological tables are a special Straits of Florida; South Carolina to Cuba; Cape Canaveral extraction from the International Station Meteorological to Key West; Alligator Reef to Habana. Southeastern U.S. Climate Summary (ISMCS). The ISMCS is a CD-ROM charts show the axis and the position of the inner edge of jointly produced by the National Climatic Data Center, the Gulf Stream from Cape Hatteras to Straits of Florida. Fleet Numerical Meteorology and Oceanography (145) Up-to-date information on the location, width and Detachment-Asheville, NC, and the U.S. Air Force maximum surface temperature of the Gulf Stream System Environmental Technical Applications Center, Operating is available in a variety of ways. Such information is Location-A. The meteorological tables for the ocean broadcast by NOAA Weather Radio stations from Key areas are compiled from observations made by ships in SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 231 19

(153)

Mean Surface Water Temperatures (°C) and Densities

Years Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean

Temp 21.7 22.2 23.7 25.8 27.9 29.6 30.4 30.6 29.7 27.6 24.4 22.3 26.3 Key West, FL 41 Density 26.8 26.9 27.1 27.3 27.5 27.2 27.3 27.3 26.9 26.6 27.0 26.9 27.1 Temp 16.7 17.6 19.7 23.1 26.4 28.8 29.7 29.7 28.7 25.4 21.0 17.6 23.7 St. Petersburg, FL 25 Density 19.7 19.6 19.4 19.5 20.5 21.2 20.6 18.6 17.1 17.5 18.8 19.5 19.3 Temp 14.4 15.7 18.4 22.9 26.4 29.1 29.8 29.8 28.3 24.2 19.0 15.4 22.8 Cedar Keys, FL 31 Density 19.9 19.1 18.1 18.1 19.1 20.2 19.9 19.0 18.8 19.2 20.2 20.1 19.3 Temp 13.1 14.3 17.1 21.6 25.4 28.6 29.6 29.7 27.8 23.5 18.1 14.2 21.9 Pensacola, FL 48 Density 13.0 11.9 9.5 8.2 10.9 12.8 12.9 12.9 14.6 15.9 17.2 15.5 12.9 Temp 16.1 16.2 17.6 20.9 25.2 28.3 29.3 29.4 28.3 25.0 21.2 18.1 23.0 Grand Isle, LA 21 Density 22.9 21.0 20.3 17.3 16.7 17.3 20.1 20.8 21.2 22.7 24.1 23.9 20.7 Temp 10.8 11.9 15.3 19.9 24.6 28.3 29.4 29.6 27.9 23.3 17.3 12.6 20.9 Eugene Island, LA 28 Density 1.9 1.1 1.1 0.8 0.6 0.6 1.0 2.4 5.7 5.5 4.7 3.3 2.4 Temp 13.1 14.2 16.8 21.4 25.6 28.8 30.2 30.3 28.5 24.4 18.8 14.8 22.3 Galveston, TX 50 Density 17.1 16.7 16.8 16.2 15.1 16.0 19.1 22.1 19.9 18.6 18.8 18.2 17.9 Temp 11.9 13.5 16.2 21.4 25.1 27.7 28.7 29.3 27.9 23.8 18.9 14.9 21.6 Freeport Harbor, TX 16 Density 18.1 17.6 18.9 18.5 17.0 19.1 22.5 24.5 20.9 18.4 19.0 18.4 19.4 Temp 16.7 16.8 19.8 23.5 27.1 30.1 30.8 30.8 29.1 25.6 20.1 16.9 23.9 Rockport, TX 7 Density 20.6 20.0 19.6 20.6 20.9 22.4 25.6 27.6 23.2 20.4 20.5 19.2 21.7 Temp 13.6 14.3 16.7 22.2 25.8 28.8 29.8 30.0 29.2 25.3 20.7 16.3 22.7 Port Aransas, TX 11 Density 22.5 23.1 23.4 22.9 21.8 24.3 26.2 27.2 24.8 22.6 22.8 23.3 23.7 Temp 14.6 16.1 18.6 23.8 26.1 28.3 29.2 29.2 28.3 24.6 20.7 16.7 23.0 Port Mansfield, TX 9 Density 25.8 26.0 26.2 26.3 24.9 24.7 27.1 30.1 29.7 28.0 28.8 27.6 27.1 Temp 14.6 15.3 17.4 21.3 24.7 26.3 25.9 26.7 28.2 25.8 21.7 17.6 22.1 Brazos Santiago, TX 14 Density 24.2 24.6 25.1 25.3 25.3 26.7 27.2 27.5 26.6 25.2 25.5 24.6 25.7 Temp 16.0 17.3 19.8 23.6 26.8 29.0 29.6 29.6 29.1 25.9 21.4 17.5 23.8 Port Isabel, TX 24 Density 24.8 25.0 24.7 25.3 25.4 26.4 27.5 27.6 25.7 24.3 25.1 25.3 25.6 Temp 26.6 26.4 26.9 27.4 27.3 28.1 28.3 28.4 28.8 28.6 28.2 27.1 27.7 San Juan , PR 10 Density 25.4 26.0 26.1 26.2 25.3 25.5 25.6 25.1 24.4 24.0 24.1 24.5 25.2 Temp 26.6 26.4 27.1 28.0 28.6 28.8 28.9 28.9 29.3 29.2 28.6 27.2 28.2 Isla Maguey, PR 15 Density 26.3 26.7 26.8 27.0 27.0 26.9 26.9 26.9 26.6 5.9 25.9 26.1 26.5 Temperature (Celsius) F (Fahrenheit) = 1.8C (Celsius) + 32

Density as used in this table is the specific gravity of the sea water or the ratio between the weight of a sea-water sample and the weight of an equal volume of distilled water at 15°C (59°F).

passage and extracted from the National Climatic Data tracks, one will occasionally stray through the region. Center’s Tape Deck-1129, Surface Marine Observations. When cold fronts push through and stall over the Gulf, Listed in Appendix A are National Weather Service they may trigger the formation of winter storms. These offices and radio stations that transmit weather systems often parallel the north Gulf coast or move inland information. producing persistent low stratus clouds and rain ahead of (154) This section presents a seasonal picture of the their centers. About one-half of the 30 to 40 cold fronts weather that can be expected to affect shipping in the that penetrate the Gulf each year bring strong north winds Gulf of Mexico and the northwest Caribbean. Detailed and whip up rough seas; these are known as “northers.” local weather is discussed in the appropriate chapters. The cold air behind the fronts can cause sudden and (155) While navigating the Gulf of Mexico presents few sometimes large drops in temperature. These cold air weather hazards, the ones that occur can be treacherous. masses lower the sea surface temperatures, which aids in Winter storms and cold fronts can generate gales and rough the formation of dense advection fog that occurs when seas. Sea fog, frequent from December through April, can warm southerlies blow across these cool waters. This fog plague the mariner in open and coastal waters. During is most prevalent along the north Gulf coast from January summer and fall, there is the threat from hurricanes. through April. (156) During winter, the region is subjected alternately (157) By May, the semipermanent, subtropical Atlantic to maritime tropical and continental polar air masses. High (Bermuda High), which extends westward across While the Gulf lies south of the primary winter storm the Gulf of Mexico, strengthens and tends to block U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 232

storms and fronts from the north. Spring is one of the the north Gulf region. Close to the north coast, rough seas most trouble-free seasons in the Gulf. Easterly moving are less likely than farther south because of the limited systems are infrequent until early summer when the threat fetch. Northers usually last 1 to 2 days but can persist for 4 of easterly waves and tropical cyclones looms over the days. The passage of these fronts often results in sudden, region. large temperature drops, particularly close to the coast. (158) The summer wind flow around the Bermuda High (164) These fronts often stall over the Gulf of Mexico. is generally from the east through south, and this is The contrast between the cold continental air to north and reinforced along much of the coast by the afternoon sea warm tropical air to south may result in the formation of breeze. These prevailing winds provide a source of moist an atmospheric wave along the front. Depending upon tropical air that results in frequent shower activity along supporting environmental conditions, the wave may the coast, particularly during the afternoon and evening. develop into a low-pressure system. These lows often Many of these showers develop into thunderstorms, move northeast or east-northeast and sometimes develop which may drift offshore at night. Infrequently, west into major winter storms off the Atlantic coast. North through north winds bring hot, dry weather to the Gulf Gulf waters are considered a region of cyclogenesis coast. from December through March, and the waters off the (159) Easterly wave and tropical cyclone activity increases central coast of Texas are particularly active. February during August and reaches a peak in September. The is usually the most active month. These low-pressure principal paths of tropical cyclones moving into the Gulf systems spread dense low clouds and rain ahead of their are from the Straits of Florida and the Yucatan Channel. centers and draw in cold air in their wakes. More than one-half of the tropical storms reach hurricane (165) Lows and northers are mainly responsible for the strength, threatening ships at sea as well as coastal strong winds and rough seas that hamper navigation from installations. This threat remains through November. fall through spring. Wave heights of 10 feet or more are (160) During autumn, the Bermuda High begins to weaken encountered up to 8 percent of the time while winds of 28 and retreat eastward, opening the way for cold fronts and knots or more blow up to 6 percent of the time. January an occasional winter storm. This increases the frequency and February are the worst months, and conditions are of gales and rough seas. However, there are still many roughest off the coasts of Mississippi, Louisiana and days of fine sailing weather. Locally, along the coast, Texas. Gale-force winds (speeds of 34 knots or more) radiation fog forms on clear, calm nights but disperses are encountered up to 2 percent of the time.

quickly with the rising sun or if the wind picks up. (166) (161) Puerto Rico and the Virgin Islands lie directly in Tropical cyclone the path of easterly trade winds throughout the year. (167) To the meteorologist, the tropical cyclone is a warm- Surrounded by warm tropical waters, the islands have core low-pressure system that develops over the warm fairly uniform year-round weather with small annual waters of the tropical oceans with a counterclockwise and diurnal temperature changes and slight wet and dry rotary circulation in the northern hemisphere. When seasons. In winter, the trades are occasionally interrupted maximum sustained windspeeds exceed 63 knots, it is by weak cold fronts from north that generate shifting called a hurricane in the North Atlantic. To the mariner, winds and provide some rain during the normally dry the tropical cyclone is a storm to be avoided, a relatively winter season. From May through November, easterly small, unpredictable system capable of generating 200- waves, which are migratory, unorganized masses of knot winds, 40-foot seas and 20-foot storm surges. clouds and showers, occasionally move through the Aboard today’s ships, the wind itself is usually not the region. Sometimes they organize into tropical storms or greatest problem. However, in open water a ship is at the hurricanes, which are a threat to the mariner and marine mercy of the combination of wind and wave. The sides of coastal facilities. Normally in summer, rain falls as brief a ship tend to act as a sail. Under certain conditions this showers or thunderstorms, the result of warm, moist air sail effect may be critical. In hurricanes, the combination being forced aloft by mountainous or hilly terrain. of this sail effect, the wave action, stress on the vessel (162) and ship’s handling can cause a vessel to capsize. The Extratropical cyclones more the mariner knows about tropical cyclones, their (163) From October through April, cold continental air habits and the areas in which they may be encountered, masses invade the Gulf of Mexico some 30 to 40 times. the better are his chances of survival. These cold outbreaks may become unstable as they (168) Rarely does the mariner who has experienced a spread across the warm water. Squalls containing thick fully developed tropical cyclone (hurricane) at sea wish clouds and heavy showers may develop, and local winds to encounter a second one. He has learned the wisdom may reach 50 knots or more. Initially these fronts may be of avoiding them if possible. The uninitiated may be accompanied by gale-force winds. About 15 to 20 of them misled by the deceptively small size of a tropical cyclone are considered by mariners to be true “northers,” with as it appears on a weather map and by the fine weather winds exceeding 20 knots. Ship observations indicate experienced only a few hundred miles from the reported that winds exceed 20 knots 5 to 15 percent of the time in center of such a storm. The rapidity with which the SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 233 19

weather can deteriorate with approach of the storm, and north of Puerto Rico and either through the Straits of the violence of the hurricane, are difficult to visualize if Florida into the Gulf of Mexico or northeast into the they have not been experienced. mid-Atlantic. October activity decreases to August levels (169) As a tropical cyclone moves out of the tropics while development is concentrated in the west Caribbean to higher latitudes, it normally loses energy slowly, and just east of the West Indies. October storms frequently expanding in area until it gradually dissipates or acquires move into the Gulf of Mexico from the southeast.

the characteristics of extratropical cyclones. At any stage, (172) a tropical cyclone normally loses energy at a much faster Locating and tracking tropical cyclones rate if it moves over land. As a general rule, tropical (173) By means of radio, the National Weather Service cyclones of the North Atlantic Region move with the collects weather observations daily from land stations, prevailing winds of the area. In small hurricanes the ships at sea and aircraft. When a tropical cyclone is diameter of the area of destructive winds may not exceed located, usually in its early formative stage, it is followed 25 miles while in some of the greatest storms the diameter closely. In the North Atlantic, U.S. Air Force and NOAA may be as much as 400 to 500 miles. aircraft make frequent flights to the vicinity of such (170) At the center is a comparative calm known as the storms to provide information needed for tracking the “eye of the storm.” The diameter of this “eye” varies with tropical cyclone and determining its intensity. Long- individual storms and may be as little as 7 miles but is range shore radar stations follow the movement of the rarely more than 30 miles. The average is 15 to 20 miles. storm’s precipitation area when it is in range. This center is the region of low atmospheric pressure (174) All tropical cyclones in the Atlantic Ocean are around which winds blow in a more or less circular routinely and continuously monitored by satellite. In course, spiraling inward in a counterclockwise direction. areas far removed from the United States and the West Winds at the outer edge of the storm area are light to Indies, satellite observations are the primary and often moderate and gusty, and often increase toward the center the only means of tracking tropical cyclones, other to speeds too high for instrument recording. Although the than ship reports. Satellite imagery, in addition to other air movement near the center of the hurricane is usually means of observation such as aircraft reconnaissance, light and fitful, the seas in this area are in most cases very also provides estimates of the strength of the maximum heavy and confused, rendered so by the violent shifting sustained winds and minimum central pressure in tropical winds which surround it. Furthermore, after the center cyclones. Bulletins are broadcast to ships several times has passed a vessel, she may expect a sharp renewal daily, giving information on each storm’s location, of the gales, with winds from a more or less opposite intensity and movement. As a further aid, the mariner direction. The hurricane may affect an area covering tens may obtain weather reports by radio directly from other of thousands of square miles. ships in the vicinity of a tropical cyclone. (171) In the North Atlantic, tropical cyclones form over (175) a wide range of ocean between the Cape Verde Islands Signs of approach and the Windward Islands, over the west Caribbean Sea (176) While National Hurricane Center warnings provide and the Gulf of Mexico. In an average year nine or ten information for locating and avoiding a tropical cyclone, tropical cyclones come to life and about six of these it is important to know the sequence of events leading to reach hurricane intensity. Early and late season tropical its passage. cyclones tend to form in the west Caribbean or east Gulf (177) An early indication of the approach of such a storm of Mexico and move in a northwest through northeast is the presence of a long swell. In the absence of a tropical direction. In both June and November an average of cyclone, the crests of swell in the deep waters of the two tropical cyclones develop every three years; one of Atlantic pass at the rate of perhaps eight per minute. Swell these usually reaches hurricane strength. By July, activity generated by a tropical cyclone is about twice as long, the spreads east to the Windward Islands, and four tropical crests passing at the rate of perhaps four per minute. The cyclones can be expected every five years. Storms have swell may be observed several days before the arrival of a tendency to move into the Gulf of Mexico or along the the storm. east coast of the United States. During August and the (178) When the storm center is 500 to 1,000 miles away, first half of September, the breeding grounds lie between the barometer usually rises a little and exhibits a slight the West Indies and Africa, while during the latter part of pumping action. Skies are relatively clear, and cumulus September they extend into the Caribbean and Gulf of clouds, if present at all, are few in number and their Mexico. During this 2-month period about seven tropical vertical development appears suppressed. Snow-white, cyclones come to life, with about four reaching hurricane fibrous “mare’s tails” (cirrus) appear when the storm strength. Early August tracks are similar to those of July, is about 300 to 600 miles away. Usually these seem to while later in the month storms move in a more west converge more or less in the direction from which the direction in the lower latitudes and either continue into storm is approaching. the south Gulf of Mexico or recurve over Puerto Rico. (179) Shortly after the cirrus appears, but sometimes This is also true for many late-September storms, while before, the barometer starts a long, slow fall. At first the earlier in the month many move west-northwest to the U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 234

fall is so gradual that it appears only to alter somewhat the (185) normal daily cycle (two maximums and two minimums in Locating the center of a tropical cyclone the tropics). As the rate of fall increases, the daily pattern (186) If intelligent action is to be taken to avoid the full fury is completely lost in the more or less steady fall. of a tropical cyclone, early determination of its location (180) The cirrus becomes more confused and tangled, and direction of travel relative to the vessel is essential. and then gradually gives way to a continuous veil of The bulletins and forecasts are an excellent general guide, cirrostratus. Below this veil, altostratus forms, and then but they are not infallible and may be sufficiently in error stratocumulus. These clouds gradually become more to induce a mariner in a critical position to alter course dense, and as they do so, the weather becomes unsettled. so as to unwittingly increase the danger of the vessel. A fine, mist-like rain begins to fall, interrupted from time Often it is possible, using only those observations made to time by showers. The barometer has fallen perhaps 0.1 aboard ship, to obtain a sufficiently close approximation inch (3 mb). to enable the vessel to maneuver to the best advantage. (181) As the fall becomes more rapid, the wind increases (187) As previously stated, the presence of an exceptionally in gustiness, and its speed becomes greater, reaching long swell is usually the first visible indication of the perhaps 22 to 40 knots (Beaufort 6–8). On the horizon existence of a tropical cyclone. In deep water it approaches appears a dark wall of heavy cumulonimbus, the bar of from the general direction of origin (the position of the the storm. Portions of this heavy cloud become detached storm center when the swell was generated). However, in from time to time and drift across the sky, accompanied shoaling water this is a less reliable indication, because by rain squalls and wind of increasing speed. Between the direction is changed by refraction, the crests being squalls, the cirrostratus can be seen through breaks in the more nearly parallel to the bottom contours. stratocumulus. (188) When the cirrus clouds appear, their point of (182) As the bar approaches, the barometer falls more convergence provides an indication of the direction of rapidly and wind speed increases. The seas, which the storm center. If the storm is to pass well to one side of have been gradually mounting, become tempestuous, the observer, the point of convergence shifts slowly in the and squall lines, one after the other, sweep past in ever- direction of the storm movement. If the storm center will increasing number and intensity. pass near the observer, this point remains steady. When (183) With the arrival of the bar, the day becomes very the bar becomes visible, it appears to rest upon the horizon dark, squalls become virtually continuous and the for several hours. The darkest part of this cloud is in the barometer falls precipitously, with a rapid increase direction of the storm center. If the storm is to pass to one in the wind speed. The center may still be 100 to 200 side, the bar appears to drift slowly along the horizon. miles away in a hurricane. As the center of the storm If the storm is heading directly toward the observer, the comes closer, the ever-stronger wind shrieks through the position of the bar remains fixed. Once within the area of rigging and about the superstructure of the vessel. As the the dense, low clouds, one should observe their direction center approaches, rain falls in torrents. The wind’s fury of movement, which is almost exactly along the isobars, increases. The seas become mountainous. The tops of with the center of the storm being 90° from the direction huge waves are blown off to mingle with the rain and of cloud movement (left of direction of movement in the fill the air with water. Objects at a short distance are not Northern Hemisphere). visible. Even the largest and most seaworthy vessels (189) The winds are probably the best guide to the direction become virtually unmanageable and may sustain heavy of the center of a tropical cyclone. The circulation is damage. Less sturdy vessels do not survive. Navigation cyclonic, but because of the steep pressure gradient near virtually stops as safety of the vessel becomes the prime the center, the winds there blow with greater violence and consideration. The awesome fury of this condition can are more nearly circular than in extratropical cyclones. only be experienced. Words are inadequate to describe it. (190) According to Buys Ballot’s law, an observer who (184) If the eye of the storm, which may be from 5 to 30 faces into the wind has the center of the low pressure on miles across, passes over the vessel, the winds suddenly his right (Northern Hemisphere) and somewhat behind drop to a breeze as the wall of the eye passes. The rain him. If the wind followed circular isobars exactly, the stops and skies clear to permit the sun to shine through center would be exactly eight points, or 90°, from dead the thin cloud cover. Visibility improves and confused, ahead when facing into the wind. However, the track of mountainous seas approach from all sides. The barometer the wind is usually inclined somewhat toward the center, reaches its lowest point. As the wall on the opposite side so that the angle dead ahead varies between perhaps 8 and of the eye arrives, the full fury of the wind strikes as 12 points (90° to 135°). The inclination varies in different suddenly as it ceased, but from the opposite direction. The parts of the same storm. It is least in front of the storm, sequence of conditions that occurred during approach and greatest in the rear, since the actual wind is the vector of the storm is reversed, and pass more quickly, as the sum of that due to the pressure gradient and the motion of various parts of the storm are not as wide in the rear as the storm along the track. A good average is perhaps 10 on the forward side of the storm. points in front and 11 or 12 points in the rear. These values apply when the storm center is still several hundred miles away. Closer to the center, the wind blows more nearly SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 235 19

along the isobars, the inclination being reduced by one storm center and its direction of travel. It is customary or two points at the wall of the eye. Since wind direction to divide the circular area of the storm into two parts. In usually shifts temporarily during a squall, its direction at the Northern Hemisphere, that part to the right of the this time should not be used for determining the position storm track (facing in the direction toward which the of the center. storm is moving) is called the dangerous semicircle. (191) When the center is within radar range, it might be It is considered dangerous because (1) the actual wind located by this equipment. However, since the radar return speed is greater than that due to the pressure gradient is predominately from the rain, results can be deceptive, alone, since it is augmented by the forward motion of the and other indications should not be neglected. storm, and (2) the direction of the wind and sea is such as (192) Distance from the storm center is more difficult to to carry a vessel into the path of the storm (in the forward determine than direction. Radar is perhaps the best guide. part of the semicircle). The part to the left of the storm The rate of fall of the barometer is of some help; this is track is called the navigable semicircle. In this part, the only a rough indication, however, for the rate of fall may wind is decreased by the forward motion of the storm, and be quite erratic and will vary somewhat with the depth of the wind blows vessels away from the storm track (in the the low at the center, the speed of the storm center along forward part). Because of the greater wind speed in the its track and the stage in the life cycle of the storm. dangerous semicircle, the seas are higher there than in the

(193) navigable semicircle. Hurricane avoidance (197) A plot of successive positions of the storm center (194) Most mariners feel that ocean-going ships should should indicate the semicircle in which a vessel is located. leave ports that are threatened by a hurricane. Despite However, if this is based upon weather bulletins, it is not a this natural caution, ships continue to be damaged by reliable guide because of the lag between the observations tropical cyclones both in port or after leaving port. This upon which the bulletin is based and the time of reception can be blamed largely on the relative unpredictability of of the bulletin, with the ever present possibility of a storm movement. In making a decision to leave or stay, change in the direction of motion of the storm. The use of the mariner must take into account the local climatology radar eliminates this lag, but the return is not always a true of tropical cyclones, the local predictability of their indication of the center. Perhaps the most reliable guide movement, the speed of movement and the suitability is the wind. Within the cyclonic circulation, a veering of the port. The Gulf of Mexico coast displays a balance wind (one changing direction to the right in the Northern of these factors. However, the reduced flexibility in Hemisphere and to the left in the Southern Hemisphere) evasion options created by the shape of the Gulf biases indicates a position in the dangerous semicircle, and a the leave/stay decision in favor of an early departure. backing wind (one changing in a direction opposite to This effectively reduces the predictability of the threat a veering wind) indicates a position in the navigable at the time of decision. The large range of storm speeds semicircle. However, if a vessel is underway, its motion affecting the section of the coast from New Orleans to should be considered. If it is outrunning the storm or Pensacola encourages an even earlier departure. These pulling rapidly toward one side (which is not difficult are considered “high risk” ports. Local factors in the Gulf during the early stages of a storm, when its speed is of Mexico further diminish the security of many ports. low), the opposite effect occurs. This should usually be For example, the strong impact of storm surge along accompanied by a rise in atmospheric pressure, but if much of the Gulf coast in places leads to closure of ports motion of the vessel is nearly along an isobar, this may due to sudden silting of their long dredged approach not be a reliable indication. If in doubt, the safest action channels. Detailed information on the vulnerability is usually to stop long enough to determine definitely the of North Atlantic ports to hurricanes may be found semicircle. The loss in valuable time may be more than in the Hurricane Havens Handbook for the North offset by the minimizing of the possibility of taking the Atlantic Ocean published by the Marine Meteorology wrong action and increasing the danger to the vessel. If Division, Naval Research Laboratory, Monterey, CA the wind direction remains steady (for a vessel which has 93943. Additional local information may be found in the stopped), with increasing speed and falling barometer, individual chapters of this book. the vessel is in or near the path of the storm. If it remains (195) The safest procedure with respect to tropical steady with decreasing speed and rising barometer, the cyclones is to avoid them. If action is taken sufficiently vessel is on the storm track, behind the center. early, this is simply a matter of setting a course that will (198) The first action to take if one finds oneself within take the vessel well to one side of the probable track of the cyclonic circulation is to determine the position of the storm and then continuing to plot the position of the one’s vessel with respect to the storm center. While the storm center, as given in the weather bulletins, revising vessel can still make considerable way through the the course as needed. water, a course should be selected to take it as far as (196) However, such action is not always possible. If one possible from the center. If the vessel can move faster finds oneself within the storm area, the proper action to than the storm, it is a relatively simple matter to outrun take depends in part upon one’s position relative to the the storm if sea room permits. But when the storm is faster the solution is not as simple. In this case, the vessel, if U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 236

ahead of the storm, will approach nearer to the center. The (204) problem is to select a course that will produce the greatest Right or dangerous semicircle possible minimum distance. This is best determined by (205) Bring the wind on the starboard bow (045° relative), means of a relative movement plot. hold course and make as much way as possible. If obliged (199) As a general rule, for a vessel in the Northern to heave to, do so with head to the sea.

Hemisphere, safety lies in placing the wind on the (206) starboard bow in the dangerous semicircle and on the Left or navigable semicircle starboard quarter in the navigable semicircle. If on the (207) Bring the wind on the starboard quarter (135° storm track ahead of the storm, the wind should be put relative), hold course and make as much way as possible. about 2 points on the starboard quarter until the vessel If obliged to heave to, do so with stern to the sea. is well within the navigable semicircle, and the rule for (208) that semicircle then followed. With a faster than average On storm track, ahead of center vessel, the wind can be brought a little farther aft in each (209) Bring wind two points on the starboard quarter case. However, as the speed of the storm increases along (157½° relative), hold course and make as much way its track, the wind should be brought farther forward. as possible. When well within the navigable semicircle, If land interferes with what would otherwise be the maneuver as indicated above. best maneuver, the solution should be altered to fit the circumstances. If the speed of the vessel is greater than (210) that of the storm, it is possible for the vessel, if behind the On storm track, behind center storm, to overtake it. In this case, the only action usually (211) Avoid the center by the best practicable course, needed is to slow enough to let the storm pull ahead. keeping in mind the tendency of tropical cyclones to (200) In all cases, one should be alert to changes in the curve north and east. direction of movement of the storm center, particularly (212) in the area where the track normally curves toward the Coastal effects pole. If the storm maintains its direction and speed, the (213) The high winds of a hurricane inflict widespread ship’s course should be maintained as the wind shifts. damage when such a storm leaves the ocean and crosses (201) If it becomes necessary for a vessel to heave to, land. Aids to navigation may be blown out of position the characteristics of the vessel should be considered. or destroyed. Craft in harbors, unless they are properly A power vessel is concerned primarily with damage by secured, drag anchor or are blown against obstructions. direct action of the sea. A good general rule is to heave to Ashore, trees are blown over, houses are damaged, power with head to the sea in the dangerous semicircle or stern lines are blown down, etc. The greatest damage usually to the sea in the navigable semicircle. This will result in occurs in the dangerous semicircle a short distance from greatest amount of headway away from the storm center the center, where the strongest winds occur. As the storm and least amount of leeway toward it. If a vessel handles continues on across land, its fury subsides faster than it better with the sea astern or on the quarter, it may be would if it had remained over water. placed in this position in the navigable semicircle or in (214) Along the coast, particularly, greater damage may the rear half of the dangerous semicircle, but never in be inflicted by water than by the wind. There are at least the forward half of the dangerous semicircle. It has been four sources of water damage. First, the unusually high reported that when the wind reaches hurricane speed and seas generated by the storm winds pound against shore the seas become confused, some ships ride out the storm installations and craft in their way. Second, the continued best if the engines are stopped and the vessel is permitted blowing of the wind toward land causes the water level to seek its own position. In this way, it is said, the ship to increase perhaps 3 to 10 feet above its normal level. rides with the storm instead of fighting against it. This storm tide, which may begin when the storm center (202) In a sailing vessel, while attempting to avoid a storm is 500 miles or even farther from the shore, gradually center, one should steer courses as near as possible to increases until the storm passes. The highest storm tides those prescribed above for power vessels. However, if are caused by a slow-moving hurricane of larger diameter, it becomes necessary for such a vessel to heave to, the because both of these effects result in greater duration wind is of greater concern than the sea. A good general of wind in the same direction. The effect is greatest in rule always is to heave to on whichever tack permits the a partly enclosed body of water, such as the Gulf of shifting wind to draw aft. In the Northern Hemisphere Mexico, where the concave coastline does not readily this is the starboard tack in the danger semicircle and the permit the escape of water. It is least on small islands, port tack in the navigable semicircle. which present little obstruction to the flow of water. (203) The rules for avoiding the storm center for power- Third, the furious winds which blow around the wall of driver vessels are summarized as follows: the eye often create a ridge of water called a storm surge, which strikes the coast and often inflicts heavy damage. The effect is similar to that of a tsunami (seismic sea wave) caused by an earthquake in the ocean floor. Both of these waves are popularly called tidal waves. Storm SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 237 19

surges of 20 feet or more have occurred. About 3 or 4 ship. The above does not take into account possible fumes feet of this is due to the decrease of atmosphere pressure or gases in the compartment; in such cases discretion and the rest to winds. Like the damage caused by wind, must be used.

that due to high seas, the storm tide and the storm surge (221) is greatest in the dangerous semicircle, near the center. Principal ports The fourth source of water damage is the heavy rain that (222) The principal deep-draft commercial ports within accompanies a tropical cyclone. This causes floods that the area of this Coast Pilot are Port St. Joe, Panama add to the damage caused in other ways. City, Pensacola, Tampa, Mobile, Pascagoula, New (215) When proceeding along a shore recently visited by Orleans, Baton Rouge, Lake Charles, Orange, Freeport, a hurricane, a navigator should remember that time is Port Lavaca-Point Comfort, Port Arthur, Beaumont, required to restore aids to navigation that have blown Galveston, Texas City, Houston, Corpus Christi, Port out of position or have been destroyed. In some instances Brownsville and Port Isabel. (See chapters 13 and 14, the aid may remain but its light or sound apparatus may respectively, for the principal deep-draft commercial be inoperative. Landmarks may have been damaged or ports of Puerto Rico and U.S. Virgin Islands.) destroyed. (223) Other ports are Key West, Port Boca Grande, (216) Sarasota, St. Petersburg, St. Marks and Carrabelle.

Cargo care (224) (217) The temperature at which condensation to water Pilotage droplets occurs is called the dew point. When the dew (225) Pilotage, with a few minor exceptions, is compulsory point is above freezing, condensation will be in the form for all foreign vessels and U.S. vessels under register of water; below freezing dew points, when reached, will in the foreign trade. Pilotage is optional for coastwise result in the formation of ice crystals deposited upon vessels that have on board a pilot properly licensed by the cold surfaces. Knowledge of the dew point along with federal government for the waters that the vessel travels. the cargo temperature and moisture content is vital for (226) Arrangements for pilots are generally made in hold ventilation decisions. advance by the ships’ agents. Pilots serving the larger (218) The relatively high humidities and temperatures ports maintain a 24-hour radio watch, while those at the encountered in this subtropical region make protection of smaller ports maintain a radio watch only when vessels are cargoes from sweat an important consideration. Critical expected. Detailed information on pilotage procedures is conditions are most likely to occur when cargoes are given in the text for the ports concerned. loaded under conditions of high temperatures, which are (227) Pilotage for vessels desiring service between ports prevalent from spring through autumn. on the Gulf of Mexico is provided by the Gulf of Mexico (219) When free air has a dew point temperature higher Pilots, Port Arthur, TX. The service, extending from sea than the temperature of the surface with which it comes buoy to sea buoy throughout the Gulf of Mexico and in contact, the air is often cooled sufficiently below its the Straits of Florida, is intended primarily for foreign dew point to release moisture. When this happens aboard vessels unfamiliar with the congested waters of the Gulf. ship, condensation will take place on relatively cool Vessels are generally boarded at their berth or, for vessels cargo or on the ship’s structure within the hold where desiring service inbound from the Straits of Florida, by it later drips onto the cargo. Thus, if cargo is stowed in launch off Miami or Key West. The Gulf of Mexico Pilots a cool climate and the vessel sails into warmer waters, provide service from the discharge point of the port pilot ventilation of the hold with outside air will likely lead to at one port to the pickup point for the port pilot at the sweat damage in any cargo sensitive to moisture. Under destination. Advance notice of 48 hours is required. such conditions external ventilation should, as a rule, be Arrangements can be made by cable (GOMPILOTS) or closed off entirely, unless the cargo generates internal telephone (409–982–2961). heat, that hazard being greater than sweat damage. In (228) the opposite case, when a vessel is loaded during a warm Towage period, and moves into cooler weather, vulnerable cargo (229) Tugs are available at all major ports; they can usually should be ventilated. be obtained for the smaller ports on advance notice if (220) A safe rule for ventilation directed toward moisture none are available locally. Arrangements for tugs should control may be stated as follows: Whenever accurate be made in advance through ships’ agents or the pilots. measurements show the outside air has a dew point (See the text for the ports concerned as to the availability below the dew point of the air surrounding the cargo to be of tugs.) protected, such outside air is capable of removing moisture from the hold and the ventilation process can be safely (230) started. Whenever the reverse is true, and the outside dew Vessel arrival inspections point is higher than the dew point temperature around the (231) Vessels subject to U.S. quarantine, customs, cargo, then ventilation will increase the moisture content immigration and agricultural quarantine inspections of the hold and may readily result in sweating within the generally make arrangements in advance through ships’ agents. Government officials conducting such inspections U.S. Coast Pilot 5, Chapter 3 19 SEP 2021 ¢ 238

are stationed in most major ports. Mariners arriving at which is 6 hours slow of UTC. When it is 1000 UTC, it is ports where officials are not stationed should contact the 0400 at Corpus Christi, Texas. Puerto Rico and the U.S. nearest activity providing that service. (See Appendix Virgin Islands observe Atlantic standard time (A.s.t.), A for addresses.) Unless otherwise directed, officials which is 4 hours slow of UTC. When it is 1000 UTC, it usually board vessels at their berths. Note: U.S. Public is 0600 at San Juan, Puerto Rico and Charlotte Amalie, Health quarantine matters for ports in Puerto Rico and the U.S. Virgin Islands.

U.S. Virgin Islands are handled by the U.S. Quarantine (243) Station, San Juan, PR. Daylight saving time (244) In all states covered by this Coast Pilot clocks are (232) Harbormasters where appointed are mentioned in advanced one hour on the second Sunday of March the text. They usually have charge of the anchorage and and are set back to standard time on the first Sunday of berthage of vessels. November. Puerto Rico and the U.S. Virgin Islands do

(233) not observe daylight saving time. Supplies (245) (234) General supplies, including fuel oil, diesel oil and Legal public holidays fuel, gasoline, water and marine supplies are available (246) New Year’s Day, January 1; Martin Luther King, at the principal ports. Similar items but in more limited Jr.’s Birthday, third Monday in January; Washington’s quantities can be obtained at many places mentioned Birthday, third Monday in February; Memorial Day, under descriptions of the different ports. last Monday in May; Independence Day, July 4; Labor

(235) Day, first Monday in September; Columbus Day, second Repairs-salvage Monday in October; Veterans Day, November 11; (236) Hull and engines of medium to large vessels can be Thanksgiving Day, fourth Thursday in November; and repaired at Tampa, Mobile, New Orleans, Port Arthur, Christmas Day, December 25. The national holidays are Beaumont, Orange, Galveston and Houston. Smaller observed by employees of the federal government and the vessels can be handled at numerous other ports. Extensive District of Columbia and may not be observed by all the above-the-waterline hull and engine repairs can be made areas in every case. at Pensacola, Pascagoula and Lake Charles. Minor (247) In addition, the following holidays are also observed repairs can be made at Freeport and Port Brownsville. in the area covered by this Coast Pilot: Marine railways are available, and repairs to smaller craft (248) Three Kings’ Day, January 6: Puerto Rico and Virgin can be made at many other places on the Gulf Coast, as Islands. listed under the descriptions of the different ports. (249) Battle of New Orleans, January 8: Louisiana. (237) Deep-sea salvage equipment is available at Key (250) De Hostos’ Birthday, January 11: Puerto Rico. West, Tampa, Mobile, New Orleans, Port Arthur, (251) Robert E. Lee’s Birthday, January 19: Florida and Beaumont and Galveston. Louisiana. (Third Friday in January in Mississippi and Alabama.) (238) (252) Arbor Day, Third Friday in January: Florida. Small-craft facilities (253) Franklin D. Roosevelt’s Birthday, January 30: Virgin (239) There are numerous places where fuel, supplies, Islands. repairs, slips for dockage and launching ramps are (254) Lincoln’s Birthday, February 12: Virgin Islands. available for small craft. For isolated places and small (255) Washington’s Birthday, February 22: Louisiana and cities, the Coast Pilot describes the more important of Virgin Islands. these facilities; for large port areas, where individual (256) Texas Independence Day, March 2: Texas. facilities are too numerous to mention, the information (257) Emancipation Day, March 22: Puerto Rico. given is more general. Additional information may be (258) Mardi Gras (Shrove Tuesday): Alabama, Florida and obtained from various local small-craft guides. Louisiana. (240) A vessel of less than 65.6 feet (20 meters) in length (259) Transfer Day, March 31: Virgin Islands. or a sailing vessel shall not impede the passage of a vessel (260) Holy Thursday: Virgin Islands. that can safely navigate only within a narrow channel (261) Good Friday: Florida, Louisiana, Puerto Rico and or fairway. (Navigation Rules, International-Inland Rule Virgin Islands. 9(b).) (262) Easter Monday: Virgin Islands. (241) (263) Pascua Florida Day, April 2: Florida. Standard time (264) Thomas Jefferson’s Birthday, April 13: Alabama. (242) Port St. Joe, Florida and the areas east observe (265) Jose de Diego’s Birthday, April 16: Puerto Rico. eastern standard time (e.s.t.), which is 5 hours slow of (266) San Jacinto Day, April 21: Texas. Coordinated Universal Time (UTC). When it is 1000 (267) Whit Monday: Virgin Islands. UTC, it is 0500 at Tampa, Florida. The area from Port St. (268) Confederate Memorial Day, April 26: Florida. (Last Joe to the Rio Grande uses central standard time (c.s.t.), Monday in April in Alabama and Mississippi.) SEP 2021 U.S. Coast Pilot 5, Chapter 3 ¢ 239 19

(269) Memorial Day, May 30: Louisiana and Virgin (276) Dr. Jose C. Barbosa’s Birthday, July 27: Puerto Rico. Islands. (277) Huey P. Long’s Birthday, August 30: Louisiana. (270) Confederate Memorial Day, June 3: Louisiana. (278) Columbus Day, October 12: Louisiana, Puerto Rico (271) Jefferson Davis’ Birthday, June 3: Florida and Texas, and Virgin Islands. (First Monday in June in Alabama and Mississippi.) (279) Thanksgiving Day, October 25: Virgin Islands. (272) Organic Act Day, June: Virgin Islands. (280) Liberty Day, November 1: Virgin Islands. (273) Munoz Rivera’s Birthday, July 17: Puerto Rico. (281) Discovery Day, November 19: Puerto Rico. (274) Constitution Day, July 25: Puerto Rico. (282) Second Christmas Day, December 26: Virgin (275) Supplication Day, July 25: Virgin Islands. Islands.