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12-1979

The Chesapeake, a boating guide to weather

Jon Lucy Virginia Institute of Marine Science

Terry Ritter

Jerry LaRue

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Recommended Citation Lucy, J., Ritter, T., & LaRue, J. (1979) The Chesapeake, a boating guide to weather. Educational series; no. 25. Virginia Institute of Marine Science, William & Mary. https://doi.org/10.21220/V5XB2Z

This Report is brought to you for free and open access by W&M ScholarWorks. It has been accepted for inclusion in Reports by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. THE CHESAPEAKE: a boating guide to BATHER jon lucy, terry ritter, jerry larue

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SEA GRANT PROGRAM Virginia Institute of Marine Science College of William and Mary Gloucester Point, Virginia Copies of this publication may be ordered for$ 1.00 each from the Sea Grant Communications Office, Virginia Institute of Marine Science, Gloucester Point, VA 23062

(804) 642-7170 THE CHESAPEAKE : a boating guide to WEATHER

by

Jon Lucy Marine Recreation Specialist Sea Grant Marine Advisory Services V irginia Institute of Marine Science And Instructor, School of Marine Science, College of William and Mary Gloucester Point, Virginia

Terry Ritter Meteorologist in Charge Norfolk, Virginia

Jerry LaRue Meteorologist in Charge National Weather Service Washington, D.C.

Educational Series Number 25

First Pri nting - December 1979 Second Printing - August 1980 Third Print1ng - August ·193·1 Fourth Printing - March 1983 Fifth Printing - March 1984 Si x th Pri nting - Feb ruary 1986 Seven th Printing - September 1988

A Cooperative Pub lication of VIMS Sea Grant Marine Advisory Services and NOAA National Weather Se rvice Acknowledgements

For their review and constructive criticism, appreciation is expressed to Messrs. Herb ert Groper, Chief, Community Preparedness Staff, Thomas Reppert, Meteorologist, Marin e Weather Services Branch and Michael Mogil, Emergency Warning Meteorologist, Pu blic Services Branch, a ll of NOAA National Weather Service Head­ quarters, Silver Spring, ; also to Dr. Rollin Atwood, Marine Weather Instructor, U.S. Coast Guard Auxiliary, Flotill a 33, Kilm arnock, Virgini a and Mr. Carl Hobbs, Geo logica l Oceanographer, VIMS. Historical climatological data on Chesa­ peake Bay was provided by Mr. Richard DeAnge li s, Marin e Cli matological Services Branch, Nat ional Oceanographic Data Center, NOAA En vironmental Data Service, Washin gton, D.C. Thanks go to Miss Ann ette Stubbs of V IM S Report Center for pre­ paring manusc ript drafts and to Mrs. Cheryl Teagle of VIMS Sea Grant Advisory Services for com­ posing the fina l text. This work is a result of resea rch sponsored (in part) by the Virgini a Institute of Marine Science Institutional Sea Grant Program , supported by the Office of Sea Grant, NOAA, und er Grant Number (NA 79AA-D-00055). The U.S. Government is authorized to produce and distribute reprints for governmental purposes notwith standing any copy­ right notati on th at may appear hereon. DES IGN BY DICK COOK Contents PAGE

CHESAPEAKE BAY CLIMATE ...... 3

GENERAL WEATHER FEATURES...... 3

Winds...... 3

Waves...... 3

Clouds ...... 5

SEASONAL TRENDS, NOVEMBER THROUGH APR IL...... 5

Fog...... 6

Co ld Air and Water Temperatures ...... 6

Co ld Fronts ...... 10

SEASONAL TRENDS, MAY THROUGH JULY...... 10

Thunderstorms...... 10

Lightning ...... 12

SEASONAL TRENDS, AUGUST THROUGH OCTOBER ...... 13

Hurricanes ...... 15

Chesapeake Bay Hurricane Ho les...... 15

Waterspouts ...... 17

SOURCES OF WEATHER INFORMATION AND FORECASTS ...... 17

WEATHER SERVICE WARNINGS -WHAT THEY MEAN ...... 20

WEATHER AND BOATING SAFETY...... 20

CHESAPEAKE BAY CLIMATE to be southerly during warm months and northerl y during the cold portion of the year. However, the The climate of t he Bay is established by its many small er bays, inlets, islands and tributaries of location in mid latitudes on the eastern edge of the Chesapeake interfere with prevailing wind flow the North American continent. This location patterns, resulting in local wi nd s wh ich can differ results in winter climate being regul ated by the drasticall y from th e general pattern. polar continental influence, whil e summer is Differences in Bay water temperature and air characterized by continental tropical weather temperature influence wind directio n and speed, with infrequent invasions of cooler air. The particularly as compared to patterns over adjacent climate is tempered by marin e infl uences which land surfaces. During cooler months, the passage of most noticeably resu lt in mi lder wi nter tem­ light, warm preva iling win ds over cold water ca n peratures than those found inl and at simi lar result in reduced win ds on the Bay as compared to latitudes. winds inland, unl ess t he warm winds are strong. Fall, winter and spring are characterized by During warmer months, whenever cold air moves occasional storm systems producing wind gusts over warm Bay water, wi nd s will be stronger and of over 50 knots*, rarely up to 70 knots, about much more gusty over th e Bay than over ad jacent once a year. Such winds usually come from land surfaces, due to the unstab le situation o f cold the south, northwest or north, but abo ut once in air overl ying rising air warmed by the water. ten years strike the area from the east, causin g Another characteristic of wi nd s around the Bay unusuall y high storm surges. is the sea breeze effect. Occurring during warmer Summers are characterized by weak low pres­ months, sea breeze is caused by differences be­ sure systems rarely producing winds as high as 30 tween air temperatures over the land and water. knots. The Bay also experiences the majority of Basicall y, air warmed over heat-absorbing land its annual average of 30 days during areas is lighter than adjacent air over re latively summer, and these, of course, may produce th e cooler Bay water. The lighter air rises, causing the hi gher winds noted formerly. Often associated cooler air o ve r the Bay to move towards land to with cold fro nts, these storms occur most fre­ fil l the void . Sea breeze is noticeable when the two quently from May through August. air masses differ by as little as 5°F (about 3°C) and Hu rricanes are experienced in the Bay about increases as differences become greater. once every ten years, generall y coming in the latter The sea breeze effect is large ly responsible for half of th e boating season (A ugust-October) . the strong d iu rna l va riation in wind speeds over the The Bay's configuration and orientati o n signi fi ­ Bay during the boating season. When no major cantly affect wi nd and weather patterns im portant weather disturbances are governing the Bay's wind to boatmen (Fig. 1 ). The rel atively straight course patterns, winds wi ll tend to be ve r y light at night, of the Bay extends in a north-south direc ti on for increasing in strength during the late morning. nearl y 200 miles (332 kilometers) . The western Maximum winds occur in mid afternoon wh en shore of the lower Bay is cu t deeply by fi ve tri­ air mass temperatures over land and water differ butaries va ryin g 2-8 miles (3 -1 3 ki lometers) in the most, with wind speed fa lling off rapidl y at width at their mouths and exhibiting northwest dusk. Such winds are ge nerall y stronger near fetches of as much as 20-40 miles (32-64 kil o­ the shore, especiall y where shore elevations are meters). On the Bay's eastern shore the numerous high er, and at the mouths of ri vers. Normal tributaries arc ge nera ll y less significant in their summer day winds may be nea rl y calm in the dimensions. The width of the Bay is greatest in early mo rn ing and increase to approximately 15 Virgini a, where the distance between shores ranges knots by mid afternoon. As a result of the sea approximatel y 11 -27 miles (18-43 kilometers) . breeze effect, better conditions for hi gh speed The Maryland area of the Bay averages 5-10 miles boating occur in the morning, while afternoons (8-16 kil ometers) in width. generally favor sailors.

GENERAL WEATHER FEATURES WAVES WIND S The state of the sea is governed primaril y by As a very general ru le, the prevailing wi nds over wi nd speed and duration, as wel l as the fetch the Chesapeake tend to foll ow its north-south (d istance) over which the wind blows. Wi nds o ri entation. Mid-channel wind s can be ex pected from the north or south have the greatest fetch

• 1 knot = 1 nautic al mile per hour (mph). 1.15 mph or 1.85 ki lometers p e r hour. 3 Figure 1. Chesapeake Bay and its major tributaries.

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4 in the Bay, but northwest winds also have a con­ siderable fetch of 2040 miles (32-64 kilometers) off the mouths of any of the major western shore tributaries. The width of the lower Bay provides considerable fetch for strong westerly or easterly winds associated with major storm systems and cold fronts. Wind takes time to affect wave height and period ( time between successive waves) . Sudden wi nd in creases or changes in direction may take a l'l hour or more to produce maximum wave heights. Choppy waves are the immediate resu lt of sign ifi­ cant changes in wind speed or direction. A sud den squall docs not build huge waves, but rather pro­ duces a chaotic sea with steep, short-peri od waves. However, if the new wind conditions persist long enough, maximum wave heights will be ach icved and can cause problems. A rule of thumb for o pen waters is, that given sufficient time, wave height wi ll increase one add itional foot (0.3 meter) for each seve n-knot increase in wind speed . Water depth and interactions of prevaili ng wave patterns with wakes from other craft can affect the nature of waves. Shallow or shoal water will increase th e steepness of waves, thereby producing dangerous choppy situations which can swamp or capsize a boat. This must be considered if one seeks the protection of the windward shore to re­ Figure 2. Effect of early June water temperatures on duce the fetch of westerly or easterly winds in the cloud cover over the Bay region. Cool air temperature over Bay . As o ne moves inside th e fish trap (pound net water (relative to that over land) inhibits cloud formation stand) li ne close to shore, the bottom frequently over the Bay during late morning and afternoon. shoals qu ite rap id ly. Boat wakes can interact with existin g waves to and may resu lt in few if any clouds over the land, produce a choppy sea, or even unusuall y high while the Bay is nearly completely cloud covered. waves if a wake joi ns wit h and enhances an existing wave. Large, swe ll -lik e wakes from commercial vessels such as fre ig hters and tankers traversing the SEASONAL TRENDS, Bay wil l a ls o be encoun tered by recreational NOVEMBER THROUGH APRIL boatmen. Much of this peri od is characterized by rough weather, and it should be treated with caution by CLOUDS the casual boatman and experienced mariner, alike. However, it is the t ime of year that many During much of the year, cloud cover over the waterfowl hunters expose themselves to t he Bay's Bay is essentially the same as that over the adjacent elements in rather fra il craft, while both ends of land mass . However, during the spring and sum­ the period encompass good boating days. The mer, whe n Bay water is cooler than the air over­ period is characteri zed by large weather systems lying the land, the cooler wa ter inhibits develop­ and storm fro nts ge nerally heralded by slowly ment of low level cumulus clouds during late increasing cloud cover and winds. As storm sys­ morn ing and afternoon hours. These clouds may tems move up the Atlantic coast in a northerly cover most of the sky over land , wh il e th e sky over or northeasterly direc tion, the st ro ngest winds the Bay wi ll be completely clear (F ig. 2). In fa ll , normally occur ahead of the storm. Over the Bay, the opposite effect resul ts when Bay water is in particular its sou thern half, the leading winds of warmer than the air over land. This situation such storms come out of the northeast quadrant usua ll y develops with the passage of a cold front with speeds of 30-50 knots and higher. Northwest

5 winds, which usually follow these storms, can be minute water droplets (). Formation of dense quite strong and gusty and may persist for several fog is more common as one moves offshore, and days. should be anticipated on unusually warm, humid Strong cold fronts also cross the Bay from west days during winter or spring. Visibility during cold to east during November through March, often pro­ season will often be near zero if winds are less duced gusty northwest or northerly winds of than 10 knots. Higher winds will produce slightly 25-45 knots over open water, while winds a few better visibility, but still much less than one mile. miles inland are considerably lighter. For example, Although it happens frequently, fog should the City of Richmond, Virginia might be ex­ never catch the observant boatman totally by sur­ periencing northwest winds of about 10 knots, prise. There are several good clues indicating that while along the shore at the Bay mouth wind fog formation is imminent. According to Donald velocities are at least 50 percent higher. The un­ Whelpley in Weather, Water and Boating (Cornell stable condition of cold air moving over the Maritime Press, Inc., Cambridge, MD, 1961) and relatively warm water, as well as reduced friction William Katsch in Weather for the Mariner (2nd surface presented by the water, are responsible Edition, Naval Institute Press, Annapolis,· MD, for the gustier winds over water. Regarding this 1977) fog formation is likely if: phenomenon, remember that a doubling of wind * Fog formed in the same area the previous velocity results in a four-fold increase in wind night and weather conditions are still re­ force, a tripling in velocity a nine-fold increase, latively unchanged etc. ( Force = Mass x Ve loci ty2). * There are sustained, warm, moist winds out Naturally, wave conditions associated with the of the south blowing over colder land or blustery winds of the period can become quite water surfaces severe and prove hazardous to small and medium * The daytime sky appears hazy and not very size boats. Problems with bad chop resulting from blue, while the horizon is ill-defined,· at winds opposing strong tidal currents are also more night, light beams appear misty pronounced during this time and have to be * The sky is clear at sunset, the wind light and considered. Northerly winds of 25 knots or higher the air humid have a long fetch down the Bay and can easily * The difference between air temperature and bui Id wave heights to 5-7 feet (1.5-2 meters) in its the dew point (determined with a sling southern extremities. Westerly winds produce psychrometer) is 10°F (5-6°C) or less and the their highest waves in the widest section of the expected minimum temperature will be close Bay, particularly east of the Potomac and Rappa­ to the present dew point hannock Rivers. At the mouths of these and other Once fog has set in, Whelpley states there are large rivers, tide and wind also can interact to certain things to look for that signal it will break further aggravate wave conditions. Easterly up: winds will produce their highest waves along the * If fog was in the area the previous day and seaside beaches and at the Bay mouth where lifted, it will likely lift about the same time northeasters can result in wave heights of 10 feet again (3 meters) or more. * If the air temperature is rising, the fog will "burn off" as the air temperature rises above the dew point; however, if moderate winds FOG are blowing, the warming trend will be slow, and if rain is falling through the fog, there Fog can become a serious problem, e~pecially will be no heating by the sun, further from January through April. Most of the Bay's slowing the warming process 30-40 dense fog days per year occur during this * Changes in wind direction or increases in period. Fog on the Bay most often forms when wind velocity can move the fog out of the warm moist air with a dew point higher than the area or lift it off the water surface, im­ Bay's water temperature moves over the area from proving visibility the south to southeast. (Dew point is that tem­ perature at which the air's moisture content reaches saturation point or 100 percent relative COLD AIR AND humidity). As the warm moist air passes over the WATER TEMPERA TURES cooler water, the air can drop in temperature to its dew point and its water vapor can condense into Fall, winter and early spring bring with them

6 TABLE 1. AVERAGE SURFACE WATER TEMPERATURES (°F)* IN CHESAPEAKE BAY

Years of Month Location Observations Jan Feb Mar Apr May Jun Jul Aug Sep I Oct Nov Dec I

Little Creek, VA 6 40 41 47 55 66 74 79 80 75 66 55 45 (Norfolk) 36 55'N 76 11 'W

Solomons, MD 32 38 38 43 53 65 74 80 80 76 65 54 43 () 38 19'N 76 27'W

Baltimore, MD 56 37 37 43 53 64 74 80 80 75 65 54 43 () 39 16'N 76 35'W

Potential Potential Hypothermia Hypothermia Period Period

* oc = .556 (°F-32)

Source: United States Coast Pilot 3, Atlantic Coast, Sandy Hook to Cape Henry, 15th Ed., National Ocean Survey, NOAA, Washington, D.C., July 1977.

low air and water temperatures that can be silent rate of loss. If in cold water with no flotation killers. Falling overboard or capsi1ing during the device, never use the drownproofing method of cooler months of the year can prove fatal, although periodically submerging the head, since this is one not directly from cl rown ing. E mersi on in cold of the quickest ways to lose body heat (Table 2). water (water cooler than 70°F or 2·1°C) quickly A flotation device allows one to assume the lowers the body's core temperature and can be a Heat Escape Lessening Position (H.E.L.P.), if problem in the Bay from October through May alone in the water, or the HUDDLE position (Table 1 ). Called hypothermia, the lowering of (Fig. 3). In 50°F {10°() water, survival time using body core temperature first results in shivering, H.E.L.P. or the HUDDLE position is approxi­ then loss of manual dex tcrity and finally muscle mately four hours, as compared to only two hours rigidity. Continued cooling brings on mental when having to swim or tread water. At mid­ confusion, which renders a person pmvcrlcss to winter Bay water tempera tu res (approximate Iy help himself. Unconsciousness soon follows, 35°F or 1.7°C}, the H.E.L.P. and HUDDLE posi­ and if cl rown i ng has not occu rrccl before core tions provide about 2.7 hours survival time as temperature reaches 85°F (29.5°C), heart failure compared to 1.2-1.4 hours for swimming or tread­ completes the scenario. ing water without a flotation device (Fig. 4). Re­ Wearing a close fitting, garment type foam member that all survival times indicated herein are flotation jacket can dramatically increase survival for the "average" person. Sm al I people cool faster time over 300 percent in cold water. The next than large people, children faster than adults and best precaution is wearing a more standard type thin people faster than fat people. personal flotation device so that you do not have Cold air temperatures can also cause hypo­ to tread water or swim to stay afloat. Heat loss thermia in boatmen inadequately dressed or whose occurs primarily from the head, chest and groin clothes got wet from spray. Multi pie layers of Iigh t areas of the body and movement causes a greater clothing provide better protection than one heavy

7 TABLE 2. PREDICTED SURVIVAL TIMES FOR AN AVERAGE PERSON IN 50°F (10°C) WATER*

SITUATION SURVIVAL TIME (HOURS)

NO FLOTATION

Drownproof ing 1.5

Treading Water 2.0

WITH FLOTATION

Swimming 2.0

Holding still 2.7

H.E.L.P. or HUDDLE 4.0

UVic Thermofloat Jacket 9.5

* Clothing worn was cotton shirt, pants, socks plus running shoes.

Source: University of Victoria research results presented at the "Cold Water Survival and Rescue Symposium" sponsored by the U.S. Coast Guard and American National Red Cross, Santa Rosa Junior College, Santa Rosa, CA, Feb., 1979. garment. If spray is anticipated, a water repellent hypothermia victims is essential, and such methods or waterproof outer garment should be worn. If are described in appropriate pa mph lets available boating in cold weather, watch fellow crew mem­ from the U.S. Coast Guard. bers for signs of sluggishness, slurred speech or Also remember that when you add wind ex­ mental confusion, all signs of creeping hypo­ posure to existing low temperature conditions, thermia. Using proper methods for re-warming the actual chilling effect on exposed flesh is much

Treading water Drown proofing No H.E.L.P. H.E.L.P. Huddle

Figure 3. Possible in-the-water survival positions,· the H.E. L.P. and HUDDLE positions provide the greatest survival times (adapted from "Cold Water Survival and You." Chesapeake Bay Magazine 8 (7), 1978. J. Groene).

8 Comparative Cold Water Survival Times 20

18 HELP POSITION I: I Cl) -~ 16 HUDDLE POSITION /f I :::, I 0 ; .c NORMAL FLOATING W/PFD : I 14 I: I w TREADING WATER :E (:· I I .:= 12 SWIMMING /: I • ....J / I I 10 ;.... / I >a:: /._.- I • ::> 8 (/) /./...- / / .I w /,•' / / (!) 6 /:.-·· ,,/ . --:.-:::'-.... -_,. /

TEMPERATURE ( Degrees F.)

Figure 4. Effect of in-the-water survival positions on survival time (Source: U.S. Coast Guard). greater than under still conditions. Brisk wind lower in still conditions. The following wind conditions in combination with temperatures chill table (Table 3) should be used to better slightly below freezing can produce the same gauge how much cold weather protection is chi IIi ng effect as temperatures 30-40°F ( 17-22°C) needed.

TABLE 3. WIND CHI LL

Equivalent Temperatures (°F}*

CALM I 35 30 20 15 10 5 0 -5 -10 I 25 .c a. I ! 10 I 22 16 10 3 -3 -9 -15 -22 -27 -34 "C a, a, a. 20 I 12 4 -3 -10 -17 -24 -31 -39 -46 -53 Cl) "C I C i 30 I 6 -2 -10 -18 -25 -33 -41 -49 -56 -64 I 40 I 3 -5 -13 -21 -29 -37 -45 -53 -60 -69

* ()C= .556 ( ° F-32)

Source: "Riding Out Winter Storms," National Weather Service, NOAA, PA 79015.

9 COLD FRONTS Warnings are issued fo r win ds of 34 knots or higher and waterspou t sigh ti ngs, Severe Thunder­ T hunderstorms arc not no rm all y experi enced storm Warnings fo r winds of 50 knots or higher during the cold months. March and April, how­ and Warnings fo r tornad ic winds when ever, bring an inc rease in such ac t iv ity. During there is good evidence that any of these condi­ these months almost always precede tions will occur within one hour. co ld fro nts, but will often decrease in intensit y after moving over colder waters. Such fronts generally move out of the western quadrants SEASONAL TRENDS, towards the cast at speeds bet ween 10-30 knots with advancement generally faster in winter MAY THROUGH JULY than in summer. Because cold fronts normall y Typically, weather in this period is fair, with have a sharply sloping leading edge, they uplift occasional storms. The land and water warm warmer air ahead of themse lves r·athcr ab ruptl y, rapidly in May, reaching peak temperatures in wi th the resu lt that such frontal storms arc usually Jul y and August. Most of the time the weather violen t. The only saving grace is that the steeply is charac terized by clear skies and li ght to mode­ sloping frontal edge also means that fron tal wea­ rate winds. However, t he most active thunder­ ther is generally limited to a ve ry narrow band or storm s of the year also occur during this period, zone. The refo re , t he violent frontal storm is producing local squalls with winds up to 50 knots usually brief in duration. o r higher. Major squall lin es frequently precede cold fronts as much as 100-·150 mil es (161-241 kilo­ THUNDERSTORMS meters). Because squall lin es frequently pack sud­ den, strong winds of 34 kn ots or more, the Na­ Thunderstorms pose considerable danger to tional Weather Service may issue a Severe Thunder­ boats because o f their· strong, gusty winds and storm or as we ll as a Special li gh tning. They are fo rm ed by rising air cu rre nts Marine Warning. A "watch" usually precedes and normally occu r dur in g maximum heating of storm arrival by an hour or more. Special Marine the Ea rth 's su rface , or from mid aftern oon th rough

Figure 5. Rapidly approaching clouds at the leading edge of a thunderstorm indicate trouble for small boats. An alert skipper will head for a protected anchorage well ahead of such storms.

10 Figure 6. With a thunderstorm bearing down from astern, these boatmen are a bit tardy J on Luc y in seeking the protection of shore.

early evening. However, cold fronts also cause move more rapidly than no rmal and sometimes warm surface air to rise up over their leadi ng edge pack in g peak wi nds of 70-90 knots. This type and li kewise can produce thunderstorms anytime storm stru ck Norfolk, Virginia, in June 1977 day o r night. Whenever the passage of such a front capsizing a head boat and tearing away the end of coincid es with the time of max imum da il y heating a fish ing pier. of th e Earth's surface, the most violent thunder­ As summer progresses, weather fro nts become sto rms usuall y result. Visible indications th at weaker, and mos t of the thunderstorms result unusuall y strong wi nds arc accompanying an from the sun heating the ea rth's su rface. These approachi ng thunderstorm may be the fol low­ sto rm s develop over the land mass to the west ing: but move more slowly than the storms of spring ,t A rapidly approaching thunderstorm with and ea rly summer. T he ir no rmal rate of approach what appears to be a heavy fog bani? under it is about 10-20 knots o r less. Du ri ng Ju ly the Bay * Unusually frequent and thunder may experi ence 8-9 days of thunderstorms, wit h in an approaching storm August averagi ng 6-7 days. * A rapidly approaching low cloud or line of Boats should head toward safe anchorage when­ low clouds, with or without a thunder­ ever a thunderstorm is considered to be approach­ storm (Fig. 5) ing (Fig. 6). Storms wil l general ly move in from the southw est, west o r northwest, but they may During spring and ea rl y sum mer about six days also come out of either the south or north. Us­ of each month inclu de thunderstorms. These uall y, thund erstorm activity observed in any of storms develop to the west over land and most the eastern quadrants is not of conce rn , since such often move out of the southwest at speeds aver­ a st orm is already past your location. Always aging 25-35 knots. A particularly careful watch head for shel ter sufficient ly in advance of an should be kept o n the occasional storm approach­ approaching thund erstorm, sin ce it frequently in g o ut of the northwest. Such thunderstorms advances at speeds greater than the normal cruising have proven to be especia ll y severe, tending to speed of most boats.

11 NOAA LIGHTN ING

The winds accompanying thunderstorms are not the only problem such weather systems pose for boats o n the Bay. Lightning from these sto rms occasionally strikes boats and is capable of doing considerable damage to property and people (Fi g. 7) . More than 100 persons arc killed annually by lightning strikes in the United States. Rad io ant ennas and sa il boat masts are the items on boats most freq uent ly hit by lightning. They should be properly grounded according to methods described in the National Fi re Protection As­ sociat io n's Lightning Protection Code of 1977. All large me tal objects aboard a boat should be connected to a ground system consisting of at least No. 8 copper wire (approximately 1 /8 in ch or 3 millimeters diameter). The ground connection may consist of any metal surface normally sub­ merged which has an area of at least o ne square foot (929 square centime ters) . Propellers, a metal rudder, ce nte rboard or keel ca n be used fo r the ground connection as wel l as copper plate affixed to the hull. Rem ember: The 60 ° arc cone of protection (Fig. 8) established over a boat by proper ground­ ing procedures docs not provid e absolu te safety from li ghtning. A d irec t strike ca n occasio nall y ", " " " "- PROTECTED ZONE -"'-"-.. / STAYS GROUNDED ,

Figure 8. The best lightning protection for small boats is provided by a proper ground system. For best results, ground the highest structure on your vessel.

12 en ter the area of prot ection, or a person aboard a stays of the mast and allowed to hang over "protected" boat can be struck by a side flash of the side into the water. lightning capable of jumping 5-6 feet (1.5-1. 8 * If the boat is near shore, seek refuge under a meters) to a ground of less resistance. bridge. A thunderstorm's el ec trica l activity can be used * After any lightning storm passes, check the to tell so mething about the storm 's distance and electrical system and compass. Lightning intensity. Be ca use ligh t travels about a million strikes have been known to alter the mag­ times faster tha n sound, t he distance in miles to netic characteristics of a boat. a thunderstorm ca n be estima ted by count ing the number of seconds between lightning and t hunder, Several add itional precautions are recommend ­ and dividing by five (sound trave ls about 1/5 mile ed by T erry Ritter, Meteorologist in Charge, or 0.3 kilomet er per second) . Natio nal Weather Service, Norfolk, Virgin ia : A sim pie A M rad io can also warn of impending thu nd erstorms and lightning problems . In add i tion * If you must ride out a thunderstorm in a to producing sta t ic in ha rmony with li ghtning boat, try to avoid shallow water; it does not disc harges fro m an ap proaching storm, the radio insulate a boat from the earth as well as ca n tell a boatman w hen the charged water area deep water. associa ted with a thunderstorm surrounds his boat. * If you feel your body hair stand on end or According to Thorn Bacon in Weather for Sports­ your skin tingle, lightning may be about to men (The Hearst Corporation, N .Y ., N.Y., 1974) strike you. Drop to your knees and bend an AM radio will prod uce loud hissing or sizzl ing forward, placing your hands on your knees. noises (a bacon frying sound} when a storm's Do not lie flat. "electrical shadow " overtakes a boat. Warn ings of an approaching storm should be A pe rson st ruc k by ligh tni ng rece ives a severe heeded <1 nd precautions taken long before rain shock and may be burned externall y as well as occu rs. In the Florida Sea Grant Publication internall y. However, the bod y retains no electrica l Boating Safely - Thunderstorms (Marine Ad visory charge and may be handled safely. A person Program, Universi ty of Florida, Gainesvi lle, FL apparently " killed" by lightning ca n often be 3261 1, 1978), Wa lter Sitarz, M iam i 's Po rt Me­ revived by prompt, prolonged mou th-to-mouth teorologica l Officer for the National Weather Ser­ resuscitation and cardiac massage. vice, emphasi1 es that in many instances of ligh t­ ning casua lties, no rain was falling at the time of the lightning strike. Frequently, strikes occurred SEASONAL TRENDS, just prior to the onse t of a thunderstorm. AUGUST THROUGH OCTOBER Si tarL recommends taking the following. light­ ning precau tions aboard a boat ca ught in a thun­ This is a fair weather period, al though ma rked derstorm, even if the boat is properly grounded: by several unusual weather phenomena. A ir temperatures begin a slow dec line during late * Remain in the center of the cabin of a summer, the decl ine becoming more rap id in lat e closed boat when possible. September and October. The inc reasingly cooler * Don't go in the water or swim until the temperatures bring a rather abrupt end to the storm passes. frequent thunders torms of July and August . Up * Keep away from any metal Fittings aboard to 6-9 thunderstorm days per mont h are ty pical I he boa/, particularly those which are for portions of t he Bay during July and August, connected lo the lightning conductive wh ile Septem ber and October produce only 1-3 (ground) system. such days. T hu nderstorms during these latter * Disconnec t the major electronic equipment t wo months, while rare, are almost always asso­ not being used. ciat ed with cold fronts that now beg in to become * Don't touch the radio equipment or wiring. mo re vigorous. * On small power boats, lower the radio The increasing frequency of cold fronts also antenna and keep a low prof"ile below the marks a slight overall in crease in the percentage freeboard. of days the Bay ex periences dense morning fog. * Ground small without sophisticated Boatmen need to become fog-wary once again, electronic systems by using a length of especially from Annapolis north. The upper battery cable which is clamped to the wire rea ches of the northern Bay ap pea r to experience

13 more fog (1-4 days per month) than other areas. dominated by high pressure systems. Particularly During September and October, the Maryland during September and October, long spells of portion of the Bay generally experiences more fair, pleasant weather prevail. It is important to foggy days than Virginia waters. Morning fog keep in mind, however, that water temperatures is the rule, with dense afternoon fog generally begin to dip below 70°F {21°C) again in October, experienced less than one day per month on the making hypothermia a danger once more for average throughout the boating season. anyone finding himself unexpectedly in the water In spite of an increasing number of cold fronts, for an extended period of time. the overall weather pattern for the period is

Figure 9. Here are some of the many Chesapeake Bay hurricane holes providing good vessel anchorages during periods of high winds.

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14 HURRICANES ton Roads* -- Cross Hampton Roads Bridge Tunnel and enter the channel to the right The fair weather of August through October behind the Tunnel island; as you enter the unfortunately brings with it one ''demon" that Bay mouth of Hampton River, be on the look­ boatmen must expect to encounter on the average out for commercial tug and barge traffic; of once every ten years--the hurricane. Virginia's proceed up Sunset Creek on the left where hurricane season extends from June 1 through two marinas handle limited numbers of November 30, with a peak between mid August transient boats; do not anchor in the and the first week of October. The activity peak Hampton River channel because of barge reflects an increase in the number of hurricanes traffic and the River's northeast orien­ spawned in the southern North Atlantic that tend tation. to track parallel to the East Coast. 3) Lower York River, north shore* -- After Although hurricanes are rare in Chesapeake passing Sandy Point, look for day markers Bay, near-hurricane force winds (greater than 64 indicating the winding channel into the knots) are not uncommon because of severe Perrin River where dockage can be found thunderstorm activity and summertime squalls. at the large marina. Drafts of seven feet This makes it important for boatmen to know the {2.1 meters) can be accommodated. Even better protection is offered further up the location of well-protected harbors that provide good landlocked water with adequate depth for river in Sarah Creek where good anchorages deep draft vessels. So-called "hurricdne holes" with water depths of 7-8 feet (2.1-2.4 are present in most Bay tributaries, according to meters) are available in the northwest Julius Wilensky in "83 Hurricanes Holes of the branch up to the repair yard and marina East Coast,, (Sea Magazine, August 1978, CPS and in the northeast branch as far as the' Publications, Inc., N.Y., N.Y., Copyright 1978). oyster packing house on the north shore. Locations of hurricane holes follow (Fig. 9), as recommended by Wilensky and Jon Lucy 4) East River, off Mobjack Bay -- Anchor (indicated by an asterisk). either in Putam Creek or in East River itself, south of Woodas Point.

Chesapeake Bay Hurricane Holes 5) Corrotoman River, lower Rappahannock River, north shore - After clearing the LOWER BAY (south to north} Grey's Point bridge, (vertical clearance of 110 feet or 33.5 meters), anchor in Western Shore either of the Corrotoman's branches; 7 foot (2.1 meter) drafts can be car­ 1) Linkhorn Bay, off Lynnhaven Bay above ried 2Yi miles (4 kilometers) up the Cape Henry* -- Enter Lynnhaven Inlet east branch, while the west branch can cautiously because of a shifting bar, but handle 8 foot (2.4 meter) drafts for anticipate a well-marked entrance channel the same distance. with water depths of 6-10 feet ( 1.8-3 meters); the Inlet and the east channel 6) Dividing Creek, north of Fleets Bay, about towards Linkhorn Bay are crossed by midway between Rappahannock and Poto­ fixed bridges with 35 foot (10.7 meter) mac Rivers - Anchor up the creek just clearances; after entering the Inlet, swing above Lawrence Cove. wide to the left towards the Great Neck Road Bridge and proceed into Broad Bay, 7) Horn Harbor, about 5 miles (8 kilometers) then through the 6 foot {1 .8 meter) deep up Great Wicomico River, north shore - Narrows into Linkhorn Bay; protected This is the best of several well protected anchorages can be found in both the south creeks going upriver. and east branches of the Bay to either side of Bird Neck Point, with shoreside facilities Eastern Shore at the ends of each branch. 8) Cape Charles Harbor* -- This harbor of 2) Hampton River, north shore inside Hamp- refuge located nine miles (14.5 kilometers)

15 north of the Cape itself can provide pro­ mouth offering good protection; fixed tection with transient docks located in the bridge under construction will have 140 northeast corner behind the Coast Guard foot (42.7 meters) vertical clearance. Station; for boats drawing less than five feet {1.5 meters), Kings Creek just north 17) Patuxent River, above the -­ of the harbor also offers protection as well Anchor behind one of many bends after as marina services, but the channel markers . the river narrows somewhat, or go up one must be followed carefully. of the creeks sui~ing your draft; the entire river is well shown on NOS Chart 9-10) Occohannock and Nandua Creeks* -­ NO. 12264. Some protection can be found in Occo­ hannock Creek up to the area of Davis Eastern Shore Wharf, beyond which water depths drop below 7-8 feet {2.1-2.4 meters). Nandua 18) Crisfield, off * -- Another Creek to the north has a somewhat tricky, commercial harbor where water depths of winding channel bordered by shoals, but at least 7 feet (2.1 meters) are available with care, protection can be found by a~d service facilities are good. running up to Nandua. 19) , Tangier Sound, behind 11-12) Pungoteague and Onancock Creeks* -­ Bloodsworth Island -- Anchor up in. the Good protection is found up Pungoteague river off the channel or in any of the many Creek in the area of Harborton; further creeks up the length of the river. north Onancock Creek provides good storm anchorage in the area of the Onancock UPPER BAY (south to north) town dock. Western Shore 13) Saxis, upper * -- Pro­ tection is available in the commercial 20) , south of Annapolis between fishing harbor for boats requiring depths of West and South Rivers -- Go up past the 6 feet {1.8 meters) or less. flashing green light and anchor between High Island and steep south shore or go up Sillman Creek (7-8 foot or 2.1-2.4 meter MIDDLE BAY (south to north} depths).

Western Shore 21) ·Little Round Bay, up , off Round Bay -- Above Annapolis one must 14) St. Mary's River, lower Potomac, north open a bascule highway bridge and nego­ shore - The new harbor of refuge dredged tiate a swinging railroad bridge (generally to 8 feet (2.4 meters) 1 Yi miles {2.4 kilo­ open), then clear a fixed highway bridge meters) up the Potomac from Point Look­ (80 foot or 24.4 meter vertical clearan.ce); out may prove satisfactory unless high anchor in Little Round.Bay west of Round water forces waves over the breakwater; Bay, staying either north or west of St. best to continue up to St. Mary's River Helena Island; creeks above and below where good anchorages exist opposite R~und Bay are also good anchorages. Pagan Point or above Horseshoe Point; Carthegena and St. lnigoes Creeks also 22) Stony Creek, off Patapsco River, south offer good 'protected anchorages. shore - Excellent protection is found in upper reaches, e.g .. between Cove 15) Mill Creek, Patuxent River, north shore and Long Cove or in Nabbs Creek, as well at Solomons -- Go up to where the creek as in other coves and creeks. widens just east of Old House Cove. 23) Mortar Creek off , north 16) Mill Creek, Patuxent River above bridge, shore -- One of several good creeks off western shore -- Another Mill Creek about Middle River; go to upper reaches of river 4 Yi miles (7 .2 kilometers) above river past the marinas; the best room and pro-

16 tection is fo und in t he west fo rk east of 12 fe et (3 . 7 meters) above mean high water can be Mart in Ma ri etta Air port (5-7 foot or 1 .5- handled. Also remember t hat if you are actually 2 .1 meter depths) . expecting the eye of a hurricane t o come ashore in you r area, the bes t pro tection in the No rthern Eastern Shore Hemisphere is in t he left rear quadrant with respect to where the sto rm's eye is expected to intersec t 24) Dun Cove, off Harris Creek, behind Tilgh­ t he coast (d etermine th e left rea r q uad rant wh ile man Island -- Ancho r in either of the fac ing away from the approaching storm along its tributaries ex tending north and nort heast projec ted track) . fro m t he cove; Harris Creek offe rs good In seeking protected anchorages, also remember pro tection where it narrows before d ividing that a hurricane usually will prod uce east or north­ into two branches; the Choptank Rive r east wind speeds of 70-100 knots, fol lowed by immediately to the south of Harris Creek lesser winds from the west or nort hwest. A hurri­ also offers good protect io n in its tributaries cane's high winds and tides also require that anchor and the bends of the ri ver above Cam­ line scope be increased from the usual 7:1 ratio to bridge . a 10:1 ratio . If a protected harb or has limited swing room for anchored craft , two anchors should 25) Trcd Avon River, nort h of en trance to be used 180 o pposed to each other. Reduce th e Chop tank River -- Good anchorages can be likel ihood of dragging by anchoring in sa nd or ha rd found above Oxford in Plai ndealing Creek mud rather than- grassy bottom or soft mud . and Trippe Creek, as well as other creeks farther up the river. Waterspouts

26) Miles Rive r, behind Tilghman Point -- Best Wate rspouts are occasionally sighted in the Bay protection is found in Leeds or Hunting and should be avoided because of their potentially Creeks on the north shore, or above the destructive nature. Stra ngely enough, the pheno­ bascule bridge in the rive r itself; Glebc and menon occurs most often during fa ir weather in Goldsborough Creeks arc also safe ancho r­ late summer and early fall . Fair-weather water­ ages. spouts are caused by cooler air overriding a body of warm moist air and are usually associated with 27) , north of -- Get be­ cloud build-up over the Bay. At the cool/warm air hind one of the river's many bends, in interface, conflicti ng wind patterns often describe o ne of the creeks to the east or anywhere circu lar patterns, producing a usually short-lived around Wye Island . column of wi nd and water with wind speeds of 50 knots or less. However, a boat struck by such a waterspout can sustain considerable damage. 28) , no rth of Kent Island -­ About 11 miles (17.7 ki lometers) upriver Another type of more dangerous waterspout on the west bank, Reed Creek provides a may form in associat ion with the lead ing edge of a good anchorage; the river on up to Chester­ cold front or the squall line assoc iated. with a town offers good protection in several front. Such waterspouts arc truly t ornados over tributaries or in the river itself behind one the water, and winds may exceed 200 knots. They of the many bends. should be avoided at all cost because of their destructive winds and low pressure interior. If a 29) , head of the Bay -- Turner waterspout appears to be approaching you r boat, Creek, 4 Yi mi les (7 ._2 kil ometers) above steer a course 90° perpendicular to the spout's the mouth on t he south shore, offers the path. A moored boat in the path of a to rn ad ic best protection, although the entrance spout should have its hatches and ports open to is narrow; good protection can also be he lp eq uali ze the pressure within t he boat as the gain ed by anchori ng off the channel at spout passes. be nd s in the rive r up to Georgetown. SOURCES OF WEA THEA Remember, the anchorages mentioned here may IN FORMATION AND FORECASTS be crowded because of their popula ri ty. If you mus t look elsewhere for good protection, look for Chesapeake Bay normally is d ivided in to two bodies of water in whi ch an extra high ti de up to forecast areas, with Win dmill Point at the mouth

17 of the Rappahannock River being the dividing Forecasts for the ocean side of the eastern point. While this breakoff point is partly a matter shores of Maryland and Virginia are called coastal of convenience, it is significant in that the portion forecasts and cover an area from Cape Henlopen, of the Bay to the north generally experiences Delaware to the Virginia/North Carolina line and fronts 6-12 hours ahead of the southern Bay area. 20 miles out to sea. The coastal forecast normally Slow moving systems also may linger 6-12 hours covers this entire area at one time, but it may be longer in, or even stall over, the lower Bay. broken into a northern and southern component Under unusually extreme weather conditions, with Chincoteague, Virginia as the breakoff point the Bay may be divided into four separate fore­ {Fig. 10). cast areas to allow more detailed forecasting. Any Prudent boatmen planning an outing on the appropriate combination of the areas may also be Bay should begin monitoring marine weather utilized for making forecasts. The forecast zones forecasts 12 to 24 hours in advance of their de­ ar.e: ( 1) north of Baltimore Harbor, (2) Baltimore parture time. Weather-wise mariners will also Harbor to the Patuxent River, (3) Patuxent River start taking mental or even written notes on basic to Windmill Point and (4) south of Windmill weather conditions in this same time frame. This Point. The tidal portion of the Potomac River (5) helps one to achieve a sense of the developing may be singled out as a fifth forecast area (Fig. weather patterns that are likely to be experienced 10). while on the Bay.

Figure 10. National Weather Service (NWS) forecast areas for Chesapeake Bay and adjacent oo offshore waters; locations of NWS VHF-FM transmitters are indicated by ( • ). • VA

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18 The most complete and current weather fore­ TABLE 5. MARINE FORECASTS casts and warnings for the Chesapeake Bay and FROM TELEPHONE RECORDINGS coastal areas are taped and broadcast over VHF­ FM radio channels by National Weather Service FORECAST TELEPHONE COMMENTS offices every 4-6 minutes, around the clock. They AREA NUMBER include the latest marine forecasts, special weather Hampton Roads (804)853-30l3 Forecaster available statements, warnings and observations for both and Vicinity (Norfolk) land and marine areas. Observations are updated 6:00 a.m. • every three hours by Weather Service personnel. 6:00 p.m., 7 days Forecasts are updated every six hours, at approxi­ a week mately 5:00 a.m., 11 :00 a.m., 5:00 p.m. and Lower Chesapeake (804 )226-4423 Can hold line for 11 :00 p.m. Amended forecasts are issued when­ Bay-Patuxent to (Richmond) forecaster between ever observed conditions d iffcr significantly from Windmill Pt.; S. 9:00 a.m. and 5:00 the taped forecasts. of Windmill Pt. p.m. at 804/l22-7411 The Weather Service's VHF-FM broadcasts also Baltimore to (202 )899-3210 Forecaster available include "Now Casts,', updated approximately Patuxent and (Wash., D.C.) between 9:00 a.m. · hourly during daylight hours. The Norfolk Weather Tidal Potomac (301 )859-5380 12:00 p.m. and 1 :00 Service combines Bay and inland information in its Now Casts, while the Baltimore-Washington Inter­ (Baltimore) p.m. - 4:00 p.m. national (BWI) Airport has expanded its Now Casts The U.S. Coast Guard also transmits weather for upper Bay areas to include data from local ob­ in format ion in combination with "Notice to servers. In both cases, wind and wave information Mariners" reports on a Single Side Band frequency are given as well as the approximate location of lo­ of 2671.4 KHz. These broadcasts are made at cal squalls showing up on Weather Service radar. scheduled times only, but have a range of 200-300 The BWI Now Casts are updated every three hours miles (322-483 kilometers). Bay forecasts are (6;00 a.m., 9 .00 a.m., noon, 3 :00 p.m. and 6 :00 made at 9:33 a.m. and 10:30 p.m. EST from p.m.) but may be removed from the air after one Group Hampton Roads and Group Eastern Shore. to two hours if weather conditions change sign ifi­ Weather warnings are broadcast upon receipt on cantly. Boatmen can then pick up the new Now the same frequency as well as on VHF-FM fre­ Cast at the next prescribed time interval. quency 157 .1 MHz (Channel 22) from Hampton National Weather Service VHF-FM transmitters Roads and Baltimore. All Coast Guard stations have an approximate line of sight range of 30-70 broadcast severe emergency weather warnings miles (48-113 kilometers), depending upon the (Special Marine Warning Bulletins) on VHF-FM sensitivity of individual receivers. The broad casts frequency 156.8 MHz (Channel 16). from these stations can be picked up on permanent National Weather Service offices throughout VHF radios carried in many boats, or on inexpen­ the Bay area also provide a telephone marine sive portable VHF radios. More expensive portable weather information service for the onshore units contain an alarm tone that is automatically mariner (Table 5). Because of the large demand sounded when weather warning broadcasts arc for this taped message service, the lines are fre­ made. Appropriate transmitter locations arc quently busy. indicated in Table 4 and Figure 10. Another source of marine weather forecast TABLE 4. information is commercial AM and FM radio TRANSMITTER LOCATIONS AND FREQUENCIES stations and television stations. Numerous stations around the Bay include marine information in Norfolk, VA 162.55 MHz (Weather 1) their regular weather forecasts. A few stations at the mouth of the Bay and in the Baltimore area Richmond, VA 162.475 MHz (Weather 3) have their own boats on the water during the boat­ Manassas, VA 162.55 MHz (Weather 1) ing season's weekend and holidays. These boats report current marine weather conditions and forecasts over the air. However, care should be Heathsville, VA 162.40 MHz (Weather 2) exercised in using only commercial radio and television stations for weather information, since Salisbury, MD 162.75 MHz (Weather 3) their forecasts and weather warnings are not always up-to-the-minute because of communi­ Baltimore, MD 162.40 MHz (Weather 2) cation delays.

19 Pertinent weather information for the Bay immediately seek protected waters. In seeki ng a region is also contained on the National Weather lee s~ore, re~ember that the strong, gusty winds Service's Marine Weather Services Chart MSC-3, associated with thunderstorms wil l come from the Marasquan, New Jersey to Cape Hatteras, North ~o uthwest to northwest direction in nearl y every Carolin a. This chart is ava il able at local marinas, instance on the Bay. chart dealers or can be ordered from: National Ocean Su rvey, Distribution Division (C-44), 6501 GA LE WARN INGS - -Such warnings are made Lafayette Avenue, Riverd ale, Maryland 20840 when prolonged win ds of 34-4 7 knots are expect­ (Cost: $1 .00). ed. In unprotected waters, 35 knot winds can build up fi ve foot (1.5 meter) waves. Only the largest A final source of weather information, grad­ boats shou ld be on th e Bay. ually being phased out, is t he warning display sign-al. Signals are posted at many marinas, Coast STORM WARN INGS - - Prolonged winds ranging Guard stations and other prominent boating be tween 48 and 63 knots warrant issuanc e of Storm centers, primarily du rin g dayli ght hours only. :Varnings. All boats and oceangoing ships should stay The signals consist of a si ngl e red pennant for a 1n port or seek out a sa fe anchorage if a Storm , two red pennants fo r a Warning is posted. warning, a single square flag with a bl ac k center for a , and two such square flags for a hurricane warning. HURR ICANE WARN INGS -- When this wa rn­ ing is issued, wind s exceed ing 64 knots arc ex­ pected and eve ry vesse l should be sec urely moored WEATHER SERVICE WARNINGS - in port or tu cked in to one of the many hurrica ne WHAT THEY MEAN holes fo rmerly listed. Moorings shou ld be doubled or strengthened to withstand the ex tra strains that SMALL CRAFT ADV ISORY -- Such advisories wi ll be pl aced upon them. If mooring at a dock, are issued when wind and sea cond itions are ex ­ all ow for in creased wa ter heights of as mu ch as pec ted to cause problems for small craft. Al though 12 feet (3 .7 meters} above normal mean high the term " small craft" has neve r been defined it water. In sure that your boat will not ride over top is considered to pertain to boats up to app rox' i- of pil es and risk being hol ed. mately 24 feet (7 .3 meters} in length. During th e Chesa peake Bay has experi enced Category I wa rm er season (Apri l-November), ad visori es are hurrica nes, which have sustained winds of 74-95 issued when winds of at least 20 kn ots are ex­ mph and prod uce a 4-5 feet (1 .2-1.5 pected, since such wind s can produce th ree foot meters) above mean sea leve l. At least once, (0.9 meter} waves. During the colder mo nt hs in 1933 , the Bay ex peri enced a Category II hurri­ (Decembe r-March}, mini mum conditions for cane, whi ch had sustain ed winds up to 96-1 '\O issuing adviso ri es are wind s of 25 kno ts, whi ch ca n mph and ge nerated a storm surge of 6-8 feet generate up to fo ur foot (1.2 meter) waves . Small (1.8-2.4 meters) above mea n sea level. Meteoro­ Craft Advisories are just what they say - advice. logists bel ieve the Bay could encounter a Category In giving this "advice" the National Weather Ser­ 111 storm with sustained win ds of 111 -1 30 mp h vice must assum e that boatmen know th e capa­ and a storm surge of 9-12 fee t (2.7-3 .7 meters). bili ti es of their individual craft and can judge whether it is safe to ve nture out in their particular WEATHER AND BOATING SAFETY area. SPEC IA L MAR INE WARN ING -- Such warn­ ings are issued when sudden strong winds of at The National Weather Serv ice provides the least 34 knots are expected. The most frequent marine weather forecasts and warnings to enhance use of Spec ial Marin e Warnings is for approaching the enjoyment and safet y of the boating commu­ severe thund ers·torms, but a wa terspout sighting nit y. T he forecast and warnin g system is not report or a strong cold front packing brief but infallib le, however. For example, thunderstorms sufficient win ds might requi re a warning. Fo re­ ca n produce dangerously strong winds over a small casters ge nerall y have rather li mited information area which escape detection by the Weather concerning the actual strength of winds in seve re Service's observation system. Therefore, boatmen thunderstorms or the area of the Bay such storms must remain aware of developing weather condi­ mi ght actuall y strike. Therefore, when a warning tions when underway and be ab le to reach safety is issued for these severe storms, boatmen should when condit ions become threaten ing.

20 APPENDIX

BOA TING SAFETY CLASSES IF ABOARD A VESSEL IN TROUBLE - GI VE:

For additional informat ion on boat hand ling, 1. WHO you are (your vesse l 's call sign and weather and boat ing safety tips, contact the U.S. name) . Coast Guard's Fifth District Office (43 1 Crawford Street, Portsmouth, VA 23705) o r the local U.S. 2. WHERE you are (your vessel's posit ion in Power Squadron and ask about enrol lment in their latitude/longitude or true bearing and dis­ boating safety classes. A comprehensive boating tance in nautical miles from a widely known home st udy course and other boating safet y geographica l point; loca l names known only information arc avai lable from the Safety Officer, in the immed iate vicinity are confusing) . Virginia Commission of Game and Inland Fish­ Indicate method of determining your posi­ eries, P. 0. Box ·11104, Ri chmond, VA 23230. tion: give actual LORAN read ings, depth of wa ter, rad iobeacon bearings, etc. Indicate wh ich information you are cert ain of and which posi tion information may be doubtful. MARITIME EMERGENCY AND DISTRESS RADIO PROCEDURES 3 . WHA T is wrong (nature of distress or diffi­ SPEAK SLOWLY AND CLEARLY culty).

CALL: 4. K IND of ass ist ance desired .

1. If you arc in DISTRESS (i.e. threatened by 5. NUMBER of persons aboard and the condition grave and imminent danger) transmit the of any injured. International Distress Call on either 2182 KHz (AM, MAE or SSB ), 156.8 MHz (VH F­ FM) or Channel 9 for Citizens Band "MAY­ 6. Present seaworthi ness of your vesse l. DAY (repeated 3 t imes) this is (your vesse l 's name and ca ll sign repeated 3 times) ."* 7. Descri ption of your vesse l ; length, type, cabin, masts, power, color of hull, supcr­ 2. If you need INFORMATION or ASS IS­ suucture and trim. TANCE from the COAST GUARD (other th an in a D ISTRESS), ca ll "Coast Guard" on 8. Your listening frequency and schedule. either 2182 KHz or 156.8 MHz (the Distress and Ca ll ing frequencies). In this si tuation you will no'rmally be shifted to a common 9. Eme rgency equipment: color and type working frequency allowing the D !STRESS of flares, ligh ts, number and description frequencies to remain open . of life jackets, flotation cushions and liferafts. * The Radiotelephone Alarm Signal (if avai lab le) should be transmitted prior to t he Distress call for 10. End your message with: "This is (your approximately one minute. The Rad iotelephone vesse l 's name and call sign) . Over." Alarm Signal consists of two audio tones, of different pitch, transmitted alternately. Its pur­ pose is to attract the attention of persons on 11 . Wait for a respo nse. If no ans we r, repeat watch and shall only be used to announce that a your call. If st il l no answer, try another distress cal l or message is about to follow. cha nnel or frequency.

21 IF OBSERVING ANOTHER VESSEL IN DIFF/­ pain or injury and whether or not the pat ient CUL TY - GIVE: is conscious).

1. Your position, and (if possible} the bearing 5. Whether or not the patient is ambulatory and distance of the vessel in difficulty. (ab le to walk}.

2. Nature of distress or difficulty. 6. Patient's temperature and pulse. Difficult breathing? 3. Description of the vesse l in distress or diffi­ cu lty. 7. Whether or not patient is bleed ing, and if so, is bleeding cont ro ll ed ? 4. Your intentions, course and speed, etc . 8. Duration of pain . 5. Your rad io call sign, nam e of you r vessel, li stening frequency and schedule. 9. Previo us s1m11a r episode (if yes, treatment and diagnosis) . The Distress Ca ll has absolute priority over all other transmissions and need not to be add ressed 10. Medicine taken and med icine avai lable. to any particular station. Any mariner hearing a Distress Call shall immed iately cease all trans­ 11. Private physician's name, phone number and missions capable of interferring with the distress hospital address. message and sha ll continue to listen on the fre­ quency which th e ca ll was heard. 12. Description o f vessel, intentions and maxi­ mum speed possib le. IF YOU HA VE A MEDICAL CASE - SEND: ·13_ Weath er: wind di rection and speed, wave 1. Name of vessel and call sign. height and visibil ity.

2. Position. Sources: Mid Atlantic Marine Communications, Fifth Coast Guard District, U.S. Coast Guard, 3. Patient's name, age, sex, race and nationality. Summer ·1979; Marine Communications for the Recreational Boater, SS IC 16772, U.S. Coast 4. Nature of problem (symptoms, locations of Guard, 1979.

22 William & Mary

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