Cyclone Plan 2018-1

Introduction The purpose of the following document is to provide assistance in planning for and dealing with cyclones during reef survey work in tropical waters of northern during our 2018/19 voyage on a 40’ catamaran. It is not an instruction manual and is not definitive. Skippers must take all information available into account and make decisions based on that as to the best course of action. The authors of the document take no responsibility for the correctness or accuracy of any part of this document. Its purpose is to provide a summary for ready reference of information gathered before heading to sea on that voyage.

At the start of the voyage none of the suggested cyclone anchorages have been visited and assessed for accuracy or suitability by the authors. All information has been gleaned from books, internet searches and personal communication. Later versions will be updated and noted where applicable once any of the anchorages have been visited.

It is likely that many of the small creeks identified as cyclone anchorages here will not be deep enough at low tide for a catamaran to float. She must be prepared to rest on the mud, as she is designed to do, for some period during low tide. Once the anchorages have been visited by our catamaran measured depths will be added to this document. Pre-cyclone procedures Monitor VHF weather and warnings from Coastal Volunteer Marine Rescue stations Daily download grib files and GMDSS warnings using Predictwind Offshore app and Iridium Go. Where possible, daily check BOM sites or have shore base do so http://www.bom.gov.au/cyclone/outlooks/index.shtml http://www.bom.gov.au/australia/meteye/ http://www.bom.gov.au/marine/index.shtml

If cyclone likelihood in your region is above Very Low

Monitor twice daily or more frequently depending on circumstances. Maintain twice daily contact with shore base.

If a cyclone forms in your area

1. Determine location of eye from BOM and local information 2. Plot probable track of cyclone using BOM and local information 3. Determine your best course of action from the following;

3.1. Continue as you are but with increased monitoring. 3.1.1. This is an option if a potential cyclone is more than 500 nm from you.

1 Cyclone Plan 2018-1 3.1.2. Consider changing plans to minimise danger.

3.2. Stay at sea and plot best course to avoid cyclone. 3.2.1. This will be your best option if a cyclone is 200 to 500 nm from you and you are at sea in an area with few reefs. 3.2.2. Immediately sail as quickly as possible away from danger until you are sure you are safe. Note the cyclone avoidance navigation instructions below. 3.2.3. While sailing away, prepare the vessel for storm force winds and seas.

3.3. Stay at sea and plot course to safest, navigable sector of winds 3.3.1. This will be the case if the cyclone is less than 200 nm from you and you are so far out to sea that there is a considerable risk you will not be able to sail to a cyclone anchorage without danger of being overtaken by the cyclone. 3.3.2. When facing an approaching cyclone (in the southern hemisphere), the safest (navigable) sector is to the left of its centre and away from its path. 3.3.2.1. If you are in the navigable sector, sail away with all possible speed on a broad reach with the wind on your port side until safe. 3.3.2.2. If you are in the dangerous sector and the wind is increasing rapidly, set the series drogue sea anchor and prepare for severe winds and seas. If the cyclone is still hours away, sail with all possible speed perpendicular to its path to get as far as possible away from the eye. Before seas become too dangerous to sail, set the series drogue sea anchor from the stern mooring cleats. 3.3.2.3. If you are in the path of the cyclone. Sail with all speed with the wind on the port aft quarter to get into the navigable sector then proceed as above. 3.3.3. If you cannot sail away due to dangerous seas or lack of sea room, deploy the series drogue sea anchor from the stern mooring cleats. 3.3.4. Prepare the vessel for storm force winds and seas

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Note this diagram shows vessels in the Dangerous sector hove-to or lying to a conventional sea anchor set from the bow. Our catamaran will be safer lying to a series drogue sea anchor set over her stern so she will face the opposite direction when lying to it in the dangerous sector.

3.4. Go to a cyclone anchorage and wait for the cyclone to dissipate 3.4.1. This is the safest option and should be done urgently if a cyclone is within 200 nm. A list of cyclone anchorages follows 3.4.2. Asses the strengths and weaknesses of the anchorage. Simply, it should be as close as possible to being sheltered from waves, wind and river flow, with soft shores and no rocks, and few or no anchored boats. Generally, a small, twisting, mangrove lined, muddy creek a good distance from the coast is safest. The further up the creek and the taller and thicker the mangroves the better. Any small enclosed area of water can suffice, provided it will not be subject to heavy river flow and the banks are high above the storm surge. The more anchor and mooring points available the better. 3.4.3. If it is in a creek or river, consider the flow may increase hugely due to heavy rain, and strong currents may exert considerable force on the boat. Moor with the bow into the flow. The helm can be used to “steer” to relieve pressure on mooring lines. Prepare for trees to be washed down with the flood. 3.4.4. Understand that the storm surge may raise water level by several metres so mooring points may become submerged and anchor scope will reduce during the worst of the storm. 3.4.5. Set as many anchors and tie off to as many strong points (trees, posts, moorings etc.) as possible.

3 Cyclone Plan 2018-1 3.4.6. Prepare for unbelievably strong winds, torrential rain and massive debris. Take everything possible off the deck, batten the hatches, lash the sails, immobilise or dismount the wind generator, place emergency supplies in a grab bag, be ready to abandon ship. 3.4.7. Make a plan B in case the boat breaks its moorings or sinks. 3.4.8. Settle back and watch the show! 3.4.9. Don’t use the engines unless urgent due to debris in the water.

Judging the relative direction of the cyclone’s centre from the vessel requires observation of the changing true wind direction. Initially, while observing the wind’s change the vessel should heave to with the wind on the port bow, as though it were in the dangerous sector.

If the wind shifts to the right, clockwise, the vessel is in the navigable sector. Sail away with the wind on the port aft quarter until safe.

If the wind shifts to the left, anti-clockwise the vessel is in the dangerous sector. If the wind is increasing rapidly, set the series drogue sea anchor and prepare for severe winds and seas. If the cyclone is still hours away, sail with all possible speed at right angle to its path to get as far as possible away from the eye. Before seas become too dangerous to sail, set the series drogue sea anchor from the stern mooring cleats If the wind does not change direction the vessel is in the path of the cyclone. Sail with all speed with the wind aft of the port beam to get into the navigable sector.

Series drogue sea anchor for our catamaran A series drogue sea anchor such as our catamaran has, when set, is weighted at its outer end and hangs in a catenary so initially the vessel moves quite rapidly then slows as more drogues begin to work. The purpose of this design is to reduce the huge strain exerted by conventional sea anchors. Our catamaran’s previous conventional sea anchor broke its rode and cracked the mooring cleat during cyclone Debbie in 2017. If the series drogue is set from the bows of our catamaran the rapid movement astern could damage the rudders and endanger the boat. Regardless of how strong the wind and big the waves, the motion of the boat will be down wind for each and every wave. Any large wave will push the boat in that direction quite rapidly. Huge waves move at great speed. The boat is designed to move bow first over the water. The bows provide low resistance and lift so will handle the rushing speeds effectively. If our catamaran is pushed astern rapidly her transom steps with the engines beneath will dig in, the aft deck which is much lower and more solid than the forward trampoline deck will dig in, and it would take a much smaller wave to damage or capsize our catamaran than if she was running forward before the waves. Some waves may flood her cockpit while she is being pushed forward but her doors are strong and protected by the cockpit seats and table. It is better to have to pump her bilges and dry the floor that repair broken rudders and drowned engines or escape a capsized boat.

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Behaviour and frequency of cyclones in northern Australia

Monthly frequency of cyclones off northwestern Australia 1988/89 to 2003/04. Intense cyclones (category 4 and 5) are shown in blue. (Source BOM web site)

Cyclones off the northwest coast do have a preferred movement. Typically, they are initially steered to the west-southwest at speeds of 5-20 km/h and then take a more southerly track as they move further to the south. Cyclones on the northeast coast of Australia are less predictable. Indeed, the southwest Pacific basin has the highest percentage of cyclones having 'erratic' tracks of anywhere in the world. (Source BOM web site)

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6 Cyclone Plan 2018-1 Cyclone anchorages Queensland

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Paluma Creek, Hinchinbrook Channel 18°22.935 S 146°12.651 E

Mourilyan Harbour 17°36.367S 146°7.499E Contact harbour or locals for best location.

8 Cyclone Plan 2018-1 Cairns – Smiths Creek 16°57.889S 145°46.522E Contact Port Authority for Port Plan.

9 Cyclone Plan 2018-1 Bloomfield River 15°55.863 S 145°21.051E

Lockhart River 12°53.678S 143°21.070E or 12°54.277S 143°23.003E

10 Cyclone Plan 2018-1 Glennie Inlet, Temple Bay 12°21.352S 143°6.145

Weipa Contact Port Authority

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12 Cyclone Plan 2018-1 Holly Inlet, Port Bradshaw 12°33.390S 136°43.620E

13 Cyclone Plan 2018-1 Arnhem Bay– North Creek, Darwarunga, Habgood, Baralminar, Goromuru and Peter John Rivers are all navigable. Tides about 4 ½ hours after Darwin with 4 – 5 m range.

14 Cyclone Plan 2018-1 North Creek 12°11.664S 136°19.106E

15 Cyclone Plan 2018-1 Darwarunga River 12°26.063S 135°56.648E

16 Cyclone Plan 2018-1 Buckingham River, 12°18.124S 135°44.949E or 12°19.491S 135°43.697E

17 Cyclone Plan 2018-1 Crocodile Island back waters, Bennet Creek 12°4.284S 134°51.950E

18 Cyclone Plan 2018-1 Jessie River, Melville Island 11°26.312S 131°1.341E

19 Cyclone Plan 2018-1 Salt Water Arm, 12°15.915S 131°13.780E

20 Cyclone Plan 2018-1 Darwin backwaters

21 Cyclone Plan 2018-1 Phoenix Inlet, Port Patterson 12°40.265S 130°29.145E

22 Cyclone Plan 2018-1 Western Australia Kimberley Coast From first look, Porosus Creek is probably the best if coming from Scott or Ashmore Reefs.

23 Cyclone Plan 2018-1 Cambridge Gulf (near Wyndham)

24 Cyclone Plan 2018-1 Helby River, Cambridge Gulf 14°44.161S 128°8.622E

25 Cyclone Plan 2018-1 Lyne River, Cambridge Gulf 14° 50.072 S 128° 4.376 E

26 Cyclone Plan 2018-1 Berkeley River 14°23.120S 127°44.087E Tide reference Revely Island Range 4.6m

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Local– From memory the first creek isn't the side creek I'd pick in the Berkley, have a feeling there are rocks at entrance and a couple of rocky places along the bottom as we have fished on them. We chose up towards where the two boats are anchored near entrance to Casuarina, we just picked a spot where it was mud both sides. The hills are higher and more shelter up there than out near the mouth of the Berkley. We did also look and reckoned we could also get up Casuarina creek a bit and use that. Not too far for us as it gets shallow and there are rocks especially up the top end.

28 Cyclone Plan 2018-1 Maia Cove, Vansittart Bay 14°13.730S 126°16.429E

Local– If caught in Vansittart have a closer look at Maia cove. You presently have a big gap with no options between Berkley and Mitchell River. We anchor out in the cove but Willie Reid had a camp up that creek around 1930's / 40's and he used to take his luggers right in there, must have used right tides and they didn't draw a lot either. Goes pretty dry especially the entrance flats etc. Only rock I recall is a small shelf edge along mangrove line just before and near the bend in creek. One of Willie's boats was burnt up there by govt blokes when they forced him out for war time, can still see the chain and a bit of spar up on mud. Think he had mangroves cut back and a landing area made there.

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31 Cyclone Plan 2018-1 Mitchell River 14°30.193S 125°40.734

32 Cyclone Plan 2018-1 Local– The creek you have chosen on the Mitchell might be ok if you could go up it further, we have taken the runabout right to very end but I don't recall enough detail. It's pretty exposed where you have chosen, no decent hills for protection.

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Porosus Creek, Hunter River, Prince Frederick Harbour 14°59.960S 125°24.666 Local– Porosus creek has a few odd rocks along the banks which can be seen at low tide. Probably one of the best cyclone anchorages, very sheltered. From everything so far it appears Porosus Creek is the best cyclone anchorage of those I have found on the coast. It has easy access, is very sheltered from swell, has very little fetch so waves will be minimal, is sheltered in most directions from wind, appears to have sufficient depth so we wouldn’t have to sit on the mud (not for much of the tide anyhow), has mud banks with mangroves to tie off to and has a small catchment so no major risk of big trees and large flood levels. I think this is where we should head to from offshore, if we had time and the winds allowed.

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36 Cyclone Plan 2018-1 St George Basin

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Local- In Regent If going to go in or out Greville pass and or Southern smaller entrance to Regent you need to be very careful. As map maker says that Greville pass goes dry on the rock bars we have sat and waited for the tide there and it just pisses in, like a waterfall over the rocks. The southern narrow Regent entrance along Irwin Island roars with whirlpools. We could do it in the big boat it's wide enough but not something we'd contemplate lightly and only at correct tide. Whole nasty area, the rocks at entrance to that channel on the sea side between it and Hanover are called Treachery point. (where cross is marked on the hand drawn map) This person is correct ' exciting' is one word for it. I'm glad we only did it in the runabout. If tide and weather right would be fine. (Note – Seems Localis calling the northern entrance Greville Pass whereas Topaz is using that name for the narrow southern entrance. Take care in either case.)

The creek to the north of Spitfire Creek may be a better refuge, with much less fetch.

Spitfire Creek, St George Basin 15°20.034 S 125°6.960E

38 Cyclone Plan 2018-1 Prince Regent River arm 15°31.808S 125°10.023E

39 Cyclone Plan 2018-1 Sampson Inlet, Camden Sound 15°30.168S 124°29.704E Quite large inlet with 1 to 2 km fetch and rock shores, but easy entry. Local– Sampson does have rock sides, but at least it's close to Kuri Bay Paspaley Pearls if you get in trouble. They bring around their barges etc and have their own moorings. Note – upstream of the barge moorings the bottom is all rock and exposed at low tide. We sat small cyclone cat 2 out last wet out in there. There are a couple of the side creeks in area that go dry that may be worth a better look.

40 Cyclone Plan 2018-1 Secure Bay 16°27.768S 124°18.076E

41 Cyclone Plan 2018-1 Cyclone Creek moorings, Talbot Bay 16°22.975S 123°59.568E

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43 Cyclone Plan 2018-1 Dampier Creek, Broome 17°56.643S 122°14.728E

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