Gusty Conditions

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Multihull Seamanship Rule:

When hit by a gust when sailing downwind bear away, ease sheets and run with it.

Gusty conditions can be treacherous to safe multihull sailing if you are not prepared for them. There are a few rules which will reduce the risk of capsize.

Multihull Seamanship Rule:

Do not carry too much sail in gusty wind.

If the wind strength is rapidly fluctuating or changing direction reef as you would for the maximum wind speed in the gusts.

A smart sailor knows what sail is needed in what wind strengths. It is possible to construct a sail area/wind strength chart - as long as you have the ability to accurately determine the wind strength. Do not get tricked into reefing for the apparent wind only. Downwind this can be disastrous when you round up to head to windward.

Multihull Seamanship Rule:

When hit by a gust when sailing downwind bear away, ease sheets and run with it.

Windward gust control

When overpowered by a gust immediately ease (or dump) the traveller and/or mainsheet. Be aware that the relative increased power on the headsail will want to drive the yacht downwind so round up slowly and in control.

Downwind gust control

Sail area is critical. Never carry too much sail. If you think you need to reef then reef.

When overpowered in a gust the correct action is to bear away and ease the sheets. Never luff up as this increases the apparent wind speed. By bearing away you effectively reduce the apparent wind and ease the pressure on the sails. As soon as the gust passes it's time to reef.

Although not unique to multihulls, getting caught 'in irons' is a lot more common. 'In irons' is the state of stalling when the multi-hull has attempted to tack or has pointed so high into the wind that all forward motion is lost and the multihull starts to drift backwards.

Multihull Seamanship Rule To get out of'irons' release the headsail, push the rudder(s) over and the boom away so the multihull sails backwards and around onto the tack required.

It is possible to manoeuvre backwards with considerable skill. As soon as the mainsail has wind coming on it from the windward side, sheet in the headsail, correct the helm and sheet in the main as you progress forward. Be aware that you will have considerable leeway (sideways drift) until you get under way.

All steering systems should have a rudder lock that stops the rudders riding into a position where they may be damaged or the steering system stressed.

How not to get caught in irons

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When initiating a tack ensure your multi-hull has enough momentum to go through the eye of the wind. If your multihull has a high aspect main and a non-overlapping headsail then it may be necessary to release the mainsail so that it does not power on until the head-sail fills on the opposite tack. If momentum is minimal then the headsail may need to be backed first to blow the bow further around.

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Handling and docking a multihull is an acquired skill.

Multihull Seamanship Rule: Practise manoeuvring in open spaces.

The ease with which a multihull is moved by the wind has a major influence on the approach to a jetty. The lighter the multihull and the larger the windage (e.g. wing masts) the more preparation is required. Catamarans with twin diesel inboards have excellent manoeuvrability. In contrast a single stern mounted outboard requires a lot of careful forethought.

Single outboard driven multihulls

Many multihulls need to be going about four knots before they will turn sharply into the wind by rudder action lone. It is an advantage to be able to steer the outboard to manoeuvre when a multihull is not moving fast enough for the rudders to have much effect.

If the wind is light you will have better manoeuvrability with the centreboard(s) up. If the wind is strong enough to cause side slipping or leeway then centreboard(s) down will help reduce this at the cost of a slightly wider steering circle.

Lines and fenders should be prepared well in advance. When approaching a jetty to windward have someone ready to secure a line from the bow and use reverse to swing the stern in. On a trimaran have the crewman on the middle hull with the line secured to the float.

When leaving a jetty think ahead about the effect of the wind. Leave a line secured to the jetty to facilitate turning if the room is tight. To ensure the line will run free never have it spliced at the end. A splice will mean a thicker portion of rope and one day it will catch on a bollard or jetty structure.

Twin motor manoeuvring

If both propellers rotate in the same direction then be aware of the significant sideways pull when the motors are given short hard thrusts. By using this knowledge it is often easier to come alongside a jetty in one particular direction. If the propellers are counter rotating ( in opposite directions) then this will not occur and coming into a jetty will require large movements of the rudders to direct water flow over the rudders to steer the stern.

Practice your approach technique when mooring up in tight areas. You need to be able to extend your 'feel' to all corners of the multihull so the width is well covered. When going into a marina berth concentrate on one hull, getting it as close as possible. Occasionally watch the fit of the other hull but if your preparation is right then only one hull needs to be parked correctly - the other will follow!


Most multihulls have straight sides so fenders are needed along the length. If the jetty consists only of posts then rubbing boards should be used. On trimaran floats the fenders need to have ties top and bottom so they can be tied around the float. This is especially true if the floats are capable of riding up in bouncing waves.

If the springs are run from amidships (as is often incorrectly done) then the bow and stern can swing and the tensioning effect is lost. Always allow for the tide. The jetty is not the place to fly a hull.

Multihull Seamanship Rule:

If in doubt when approaching a jetty do a false run to test windage and current.

Mooring up

Tie up your multihull correctly. Many trimarans do not have cleats on the outer floats and the lines have to be run inboard. There are four lines needed. The head rope and the stern rope should run from the bow and stern away from the boat at about 45 degrees to the quay. This will allow for tidal range. Springs should always be rigged from the bow and the stern and should run at least the length of the hull. The springers should be as tight as possible. This will ensure the hulls cannot rotate to damage the bow or transoms.

Chafe is a major mooring problem. Protect lines running over jetty boards with hose. Look at the fairleads, rigging and deck fittings for potential chafe points.

When tying up tie a knot that can be undone. Multihulls with a high windage work their mooring lines heavily and a bowline reduces the strength of the rope by about 50 percent and can be impossible to untie when under strain. It is better to use a round turn and two half hitches. This will not jam under strain, it grips the object tightly (thus not suffering as much chafe) and will not slip or spring apart. Always use four separate lines for mooring up. If the one line is used for a spring and a head or stern rope then adjustment cannot be done without interfering with others. Ideally each line also should have its own cleat.

Mooring alongside another yacht

Rafting up to another multihull can be a nightmare if there are not enough cleats. Running rope across outboard hulls creates treacherous trip lines and potentially allows the hulls to 'work' up against one another and force fenders out. ideally the outboard hulls can be firmly secured with four lines as against a jetty.

If the yacht inside is on a jetty then the wide beam of a multihull increases the load on the inner yachts lines. Run lines from your multihull to the jetty for added support. These should originate on your outer hulls bow and stern.

If the windage is high then consider laying an anchor to secure the raft square.

Beam wind jetty handling

One of the more awkward manoeuvres is leaving a jetty with a beam wind pushing your multihull onto it. There are two techniques depending on how many motors you have.

One of the more awkward manoeuvres is leaving a jetty with a beam wind pushing your multihull onto it. There are two techniques depending on how many motors you have.

• Catamarans and Trimarans with central motors.

If possible angle the drive force so that the side force of the propeller is combined with the spring line. When the multihulls stern is clear in the channel drive in reverse to leave the jetty.

• Catamarans with twin motors in each hull.

It is really possible to spin the boat in its own length. Ensure the fenders are up to the job and use forward thrust on one motor balanced by reverse thrust on the other. Once

• Catamarans with twin motors in each hull.

It is really possible to spin the boat in its own length. Ensure the fenders are up to the job and use forward thrust on one motor balanced by reverse thrust on the other. Once

Liferafts come in soft and hard packs. Soft packs are lighter but less weather resistant unless the actual raft is vacuum sealed and completely watertight. The type of pack you need is very much dependent on the storage position. An advantage of soft valise packs is that they are more readily passed through an escape hatch if stored inboard.

The use of a liferaft on a capsized multihull needs careful thought. Liferafts, once inflated, are easily damaged if not tethered correctly. The raft should only be inflated if absolutely necessary.

Some multihull sailors say they do not need to carry a liferaft because their multihull cannot sink. A multihull surfing down the face of a wave and hitting an immobile humpback whale does not sink. It just breaks into little pieces. Liferafts are a back-up. Stay with your multihull until there is nothing left.

Multihull Seamanship Rule: Only ever step up into a liferaft.

Destruction can occur through impact or fire. A dinghy is useful but it is not a liferaft. A dinghy will not have automatic carbon dioxide inflation, automatic canopy, water, ballast bags or survival equipment. Human nature will usually ensure that the dinghy has been previously used and something will be missing or broken.

Positioning of a liferaft on a multihull needs careful thought. It needs to be accessed from both the upright and capsized position. This can be as simple as having it tied to the trampoline netting with a knife lashed and taped on both sides. It could also be stored in a locker that is accessed in both positions. If you are having a yacht designed or built then this is the best time to arrange liferaft stowage. Too many multihulls stow the liferaft as an afterthought and it ends up in an exposed position where wind driven salt or rain water can slowly penetrate the raft and shorten its life.

Lightning is a real problem on every yacht. Over 10 percent of all fatalities on cruising yachts are from lightning strikes. Most marine authorities lay down recommendations for lightning protection but very few multihull (and other yacht) sailors adhere to them. There are a few lightning problems specific to multihulls. First a general overview about the problem.

Lightning is a multidirectional flow of charges exceeding 200,000 amperes at over 30,000 degrees Celsius for a matter of milliseconds. Clouds with strong updraughts and downdrafts generate high electrical charges. When these charges reach a high enough level then cloud to ground or cloud to cloud discharges occur.

The area of most lightning strikes is under the dark area of a cumulo nimbus storm system. First you will be hit by the increased wind turbulence, then a rain area before entering the dark high risk lightning zone. As the storm cell moves along the secondary rain area at the back of the system may announce your exit from the higher risk area.

Lightning protection systems

Lightning usually strikes the highest point and takes the path of least electrical resistance to ground. In the ideal situation this route is via a mast spike (a copper rod with a pointed end) through a sufficient cross sectioned purpose placed cable to a large, separate ground plate. The spike should be at least 15 cm above other masthead equipment (including VHF aerials).

The grounding for multihulls

Aluminium multihulls can ground via connecting the mast base or mast step to the hull metal with a large, low resistance bonding strap.

Wooden or fibreglass multihulls need a large separate ground shoe. Never bond the lightning system to machinery, electrical system negatives, radio earth plates or any bronze through hull systems.

Emergency ground

Clamp a heavy gauge copper cable to about half a metre of stay. The other end should be clamped to a ground plate and hung in the water. Chains and anchors are ineffective.



Lightning safety

Stay in the hulls or bridgedeck cabin.

Avoid all metal mast fittings including the mast compression post and chainplates

If struck by lightning without adequate protection you will probably lose all electronics. Take down your position, bearing and speed at regular intervals during electrical storms.

Turn off all electronic equipment, isolate them if possible. Disconnect aerials.

Do not operate radios unless in extreme emergency. A hand held VHF is a great backup should lightning blow all electronics.

After a lightning strike.

Your compass may be incorrect. It should be swung (tested for error on all points) before being used for safe navigation.

Check all running rigging and fittings.

Check all through hull fittings - especially chainplates, log fittings and stern glands.

Man overboard prevention

Lifelines do not stop people falling off. If you are the only one on deck wear a safety harness in all conditions.

Multihull Seamanship Rule: One hand for the boat.

Multihulls accelerate and turn quickly, causing the unwary to lose balance. Toe lines around the edge (height 25 mm minimum), lifelines (height 600 mm minimum, gap 380 mm maximum), good non-slip (where it is needed) and well placed hand holds all help moving about safely.

The leeward stays are often loose -especially if your multihull has a rotating mast. Do not use this for support.

Multihulls move quickly. Wear a safety harness and connect the lifeline when on deck.

Multihull Seamanship Rule: One hand for the boat.

What to do if the man overboard is visible. Man overboard while beating or reaching

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