Capsize is very unlikely in most modern catamarans, but should the worst happen it is as well to be prepared, says Nigel Irens

YW Cat Sailing Techniques logoDifferent strategies for keeping a catamaran safe from the risk of capsize have been discussed in other features in this series, but we do need to look more closely at this particular ‘elephant in the room’.

The first thing to say is that as a general rule floating home-type catamarans are, in principle, less likely to be at risk than those designed with performance in mind.

That said, before making such a sweeping statement it’s important to mention that the level of risk involved is much more about the skill and experience of the skipper than about the qualities of the boat on which he or she goes to sea.

Over the years buyers of catamarans have tended to go more and more for the model with enhanced accommodation space (and de facto diminished performance). The bottom line is that in sailing on most ‘charter spec’ catamarans you’d have to be trying hard to win a bet to bring about a capsize.

Building catamarans down to a budget often seems to result in under-sizing of deck gear so that powering up the rig is not really possible. This really is not intended as a criticism – just a reflection on the real-life economics of this market.

If these factors combine make such a catamaran very hard to capsize then this could surely be perceived as a positive result.


Once the discussion turns from the prevention of capsize to the reality of it information and advice is not readily available. There are two different areas that need to be addressed.

The first is about actually surviving the incident in the short term. The second assumes you have managed to do that and is about surviving life on an upturned boat while summoning some help as soon as possible.

Rule one is that if you are on the inside of the boat you should immediately get away from the bridgedeck and head for one or other of the hulls as fast as possible. That’s easier said than done because you’ll be disorientated – especially if it’s dark outside and any lights inside won’t last long.

At the very least if sailing in challenging conditions (especially on a performance boat) it makes sense to bed down between watches in a hull rather than in the central saloon.

Not likely in a cruising cat!

Not likely in a cruising cat!

The reasoning is that the boat is unlikely to be supported by the roof for very long when inverted and as she settles down in the water the bridgedeck will soon be close to the water, making an exit attempt risky – especially if there are warps washing around the cockpit.

Stay below if possible

As the hulls themselves are by definition watertight the boat will be buoyant enough to float with (at worst) the threshold of the companionways into the hulls at the surface.

It’s important not to rush for the escape hatch (fitted to the inboard side of each hull) because, although it provides a useful source of light, opening it will let some of the air that’s supporting the boat out of the hull, causing it to float lower in the water.

It is probably best to wait and take stock of the situation – together with anyone else who is in the same hull – and maybe wait for daylight if the capsize has happened at night. Try to find out if others are outside – or perhaps in the other hull.

If, on balance, the decision is taken to leave the hull then it is important to make a plan that results in the hatch being open for as short a time as possible.

Catamaran escape hatch

Catamaran escape hatch


Clearly if the level of seawater inside the hull is high it is not going to provide a suitable environment for survival while waiting for assistance, so exit is the only option. If on the other hand it is only knee deep then the hull may be the place to stay.

Once again good planning for the worst before going to sea is the way to go and there is plenty of information available about that.

Discussion and planning

As part of the preparation for these dire circumstances it is important to have had a frank discussion about this whole scenario with the supplier of the boat. Has anyone ever capsized this particular design before, and what was learned from that?

Comparing the relative dangers of being at sea in a catamaran that could capsize with those of being in a monohull that could sink has always been a source of lively debate.

The truth is that there are now (and there have always been) risks in going to sea in any vessel. Our best hope in minimising that risk is to face the subject full-on and become as well informed as possible.

Man overboard

While discussing safety issues in the context of catamaran sailing we should take a brief look at that other seafarer’s nightmare – losing a man overboard.

All the normal recovery procedures apply to a catamaran with regard to the all-important location of the casualty, but there are some important differences in the way the approach is made for the recovery.

Because of the high windage of a catamaran and relatively small amount of lateral resistance under the water you can assume that, as you slow the boat down to attempt the pick-up, you’ll make a huge amount of leeway. As a result if you approach to windward of the casualty there is a real danger that the casualty’s legs will be carried under the leeward hull – with a real risk of serious injury from the propeller.

Because of high windage it can be a problem approaching a casualty in the water

Because of high windage it can be a problem approaching a casualty in the water

To be absolutely safe from this peril just keep to leeward of the casualty. Of course this means that, despite you best efforts, you could pass too far to leeward and won’t be able to get a line to them.

A good way to avoid this problem is to motor at maybe two to three knots across the wind trailing a long line behind the boat (from the leeward stern). You should aim to pass at least 10m to windward of the casualty – which should be easy to judge because you have enough speed to have good steerage way.

Because the casualty will need to hang onto this line it should be easy in the hands – a 14-16mm 8 plait nylon mooring line or similar would be ideal.

When the casualty is directly to leeward of you turn sharply downwind, making a 180° turn that leaves you passing safely to leeward. Slow down at this point, being careful not actually to go astern and risk getting the line around the leeward propeller.

If all goes well the bight of the rope will now be encircling the casualty and at some point he or she will be able to grab hold of it.


From now on you shouldn’t need to engage the drive to either propeller. Keep the helm to leeward and the boat should lie with the wind somewhere on the quarter. If you’re moving too fast – making things difficult for the casualty – you could transfer the line to the bow so that the drag of towing will tend to make the boat round up somewhat – you should be able to control the angle at which the boat lies to the wind by moving the attachment point of the rescue line to different points along the sheer.

If all goes according to plan you should be able to haul the casualty in to the windward quarter of the boat, where they can use the emergency boarding ladder.

If they are not up to that then it should be possible to pass them another rope with a bight in the end of it big enough for them to pass it over their shoulders and under their arms so that they can be hauled aboard.

Do’s and don’ts

  • DO take positive action to wise up on the risk of capsize on the catamaran you sail. Asking difficult questions of boat suppliers and collecting opinions from other owners are all valid.
  • DO develop some kind of basic plan for the worst case – such as impressing on crew that if below in high-risk conditions then being in the hulls is much safer than being on the bridgedeck. In the case of a man overboard do always make the pick-up from a position downwind of the casualty.
  • DON’T take the word of some designer who’s never capsized as gospel – ferret around online and find out what conclusions people who have actually been there have drawn from their experience.
  • DON’T risk sailing in bad weather until you have plenty of experience with the boat in more moderate conditions.
  • DON’T even think of steering by autopilot when in potentially dangerous conditions. Many accounts of capsize reveal that there was no one on the helm at the critical moment.
  • DON’T make a meal of all this. Capsize is very unlikely in most cruising catamarans, but it does happen occasionally so, as with most seamanship issues, the smart move is to be on top of the subject and prepared for the worst.

Our eight-part Catamaran Sailing Skills series by Nigel Irens, in association with Pantaenius, is essential reading for anyone considering a catamaran after being more familiar with handling a monohull.

Part 8: the future of catamaran cruising

AY7Q3617Series author: Nigel Irens

One name stands out when you think of multihull design: the British designer Nigel Irens.

His career began when he studied Boatyard Management at what is now Solent University before opening a sailing school in Bristol and later moving to a multihull yard. He and a friend, Mark Pridie, won their class in the 1978 Round Britain race in a salvaged Dick Newick-designed 31-footer. Later, in 1985, he won the Round Britain Race with Tony Bullimore with whom he was jointly awarded Yachtsman of the Year.

His first major design success came in 1984 when his 80ft LOA catamaran Formule Tag set a new 24-hour run, clocking 518 miles. During the 1990s it was his designs that were dominant on the racecourse: Mike Birch’s Fujicolour, Philippe Poupon’s Fleury Michon VIII, Tony Bullimore’s Apricot. Most famous of all was Ellen MacArthur’s 75ft trimaran B&Q, which beat the solo round the world record in 2005.

His designs have included cruising and racing boats, powerboats and monohulls, but it is multis he is best known for.

See the full series here

A special thanks to The Moorings, which supplied a 4800 cat out of their base in Tortola, BVI.

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