Quote:
Originally Posted by Highland Fling
well someone managed to capsize a Chris White Atlantic 57 that is a big cat to flip over
read (almost) all here
Press Chris White Designs High Performance Cruising Catamarans
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Also see the owner's account and epilogue at
LossOfAnna. Very relevant reading and he is painfully honest about the
mistakes he believes he made. Given that the last
wind speed they
recall seeing was 62 knots, and they believe the highest winds were significantly stronger, they were probably in
hurricane strength winds (or close enough) at the moment of capsize.
I don't want to engage in second guessing the
captain and crew of s/v Anna, I was not there so I don't know all the details first hand, but her loss does point out that sudden extreme gusty winds are a potential
danger for catamaras. After reading about the loss, I started thinking about my experiences in similar conditions (Chris White also published one of his in response). Big dramatic gusts are certainly a concern for cats, but there are techniques, which if used immediately, can be successful in dealing with such conditions. I thought it might be worthwhile for the forum, and on-topic, to post my experiences and opinions here.
I've done a lot of
multihull sailing in the
Gulf of Mexico and Western Carib where strong squalls are common. Below is a discussion of the techniques I have used successfully to handle these conditions.
When
wind speed increase is dramatic and almost instantaneous you must act immediately to change the wind loads on the
boat. Any action that takes more than a few seconds to initiate is a waste of precious time and just increases your risk. You don't have time to reef, drop
sails, deploy
sea anchor, etc. You must act and change something right now. This essentially only leaves you with quick adjustments to
sheets and/or
helm. Actions that fall into this category are:
-
Dump the main. Anyone who has done a lot of sailing on small high-performanace cats like Hobies has almost certainly learned from experience to never let the main sheet leave your hand -- especially in gusty conditions. This is your most immediate saftey valve. That big
mainsail, so common on modern cruising cats, can become a liability very quickly (IMHO it is not the ideal sail plan for a cruising
multihull, but that's another subject...). In a big gust you can depower very quickly by simply dumping the main (careful though on big cats the main sheet can be extremely heavily loaded). Never leave the main sheet on a
winch -- keep it close at hand and ready to run -- ideally on in a cam cleat or something which can be quickly released.
-
Pinch/Luff. Head-up, ease
sails, bleed off the force of the wind. Control the luffing as much as possible to minimize damage to sails,
rigging, and crew. This was Chris White's choice in similar conditions to those of S/V Anna (which he discusses on the originally posted link). Not my favorite due to the flogging
rigging, but it works.
-
Run with it. If you have sea room and the seas are not too large (which they typically are not in sudden squall winds because they do not have time to build), then turn and run with it. The change in apparent wind, especially on a faster
boat, is dramatic and greatly reduces healing forces. In a similar situation to S/V Anna's, in the
Gulf of Mexico once we had squall winds explode from 5 knots to 50 instantaneously. We had an advantage though -- I suspected it was coming -- I was
watching this beast visually and on
radar -- expected it to get ugly and we were arleady deeply reefed when it hit. Seas were relatively calm, so I chose to turn and run with it, we went from 50+ knots apparent to 38...way big difference in wind loads and a nice easy controlled ride till it blew itself out about 30 minutes later (made great time too, but in the wrong direction).
-
Heave-to. Quickly heave-to and ease the main way out till it luffs. This reduces effective sail area, there's minimal flogging of the main and rigging (assuming a typical fully batten main on a catamaran), and the boat is in a nice stable attitude (more so than heading up and luffing). Stay hove-to and let it roll over you. I have also done "pre-emptive" heave-to's before -- If you see it coming, and expect it to be ugly, then heave-to before it even gets to you. One other potential advantage of this tactic is that the squall may pass over you more quickly since you are staying put. It is also easier on the crew than running with it and can be used even in big seas. While in a hove-to attitude it is also much easier to make other heavy
weather preparations if necessary (pull another reef in the main, rig a
drogue, etc). Or, just sit down, have a cup of coffee and let it blow.
The final call of course depends upon the circumstances, boat, and crew, but the choice must be made very fast.