Corsair F-27 - capsize?

[Corsairquestions]

First let me say my sailing experience has been limited- Sailfish as a kid, crewing a 44' Luder yawl MANY years ago in college, and Hobie Cat 16 all last summer.

This weekend I went out with a neighbor on his F-27. It was a very nice boat, and a pleasurable sail until we headed home (relatively shallow, wide, coastal river). In an attempt to eliminate one tack, we were running along the lee shore at about 5-6 knots, pointed up high and sheeted in, when the wind really started blowing- 20 -25+ kts(?) with solid 3' - 4'+ white caps. Were were only doing 5+ kts with the main luffing almost continuously (neither the main nor the jib were reefed) when we attempted to change tack. We had so little way on that the wind, and waves kept the bows from coming through the wind and the bow came back through the wind (we were likely backing at this time). (The following all happened quickly) She heeled over pretty far, and dark water was coming over the top of the lee (left) ama as we were being blown sideways. I tried to provide the skipper, who I had just learned had only sailed the F-27 twice before and had an unknown amount of other sailing experience, with some recommendations. It appeared that the skipper had some tiller reversal problems too. Anyway, the lee ama continued to dig in while we drifted towards shallow water and the shore. I looked aft and noticed the skipper still had the main fully sheeted in. I jumped aft, uncleated the main, and took over the tiller. I got her on a good heading and trimmed the main sheet. He reefed the jib while I carefully sailed in this little squall, upwind, across the river. Except for problems dropping the main we got home with no further problems.

Sorry for the long tale, but my question is- could the F-27 have capsized with 20 - 25kts of wind right on the beam, with the main and jib fully sheeted in?

(It is a lot easier to tell when and if my Hobie Cat is going over.)

[sailingdog]

Yes, you could capsize a F27 trimaran in 25 knots of wind with the unreefed main and jib fully sheeted in. The most common cause of larger multihull capsizes is being over-canvassed and then making a mistake. Turning the boat quickly or steering into the waves the wrong way can both contribute to capsizing a multihull that is over-canvassed.

In a shallow river, if you have a situation where the wind is running against the current, you can get significantly higher waves than you would expect, and they can be very nasty to deal with and if the boat is being pushed hard, may be enough to get you past the point of no return.

When you're sailing a multihull in stronger winds and don't have her reefed for the conditions, the mainsheet should NEVER be cleated off.

You and your neighbor really need to learn to reef the boat properly for the given conditions, and sail her conservatively, at least until you have enough experience to understand the dangers and what is really going on. Years of monohull sailing don't really train you for sailing a multihull, since some of the reactions for certain situations are different for a monohull than what would be appropriate on a multihull.

BTW, you reef a multihull for the peak or gust wind speeds, where you reef a monohull for the average wind speeds. The reason for this is very simple—a monohull can usually bleed off the excess power of a gust by heeling the boat over.... a trimaran or catamaran can't do that. However, multihulls are generally lighter for the given sail area and will accelerate during a gust more than a monohull will, and need less sail in strong winds than a monohull does.

A beach cat, like your Hobie 16, isn't going to give you much real help in understanding how a larger multihull is going to react, since the beach cats are generally way over-canvassed, have a relatively narrow beam and relatively little floatation in their hulls. A trimaran, like the F27, will give you plenty of warning signs....but unless you know what to look for, you'll miss most of them and end up in trouble.

A couple of warning signs on a larger trimaran are:

1) If you start flying the main hull or the main hull starts to lift.
2) The leeward ama starting to submerge.

Also, while a multihull can go fast....sometimes it just makes sense not to go as fast as possible. I've been out in weather where we could have put up a bit more sail and gone 15-17 knots...but it is a lot more comfortable to reduce sail and cruise at 9-12 knots.

Finally, a common mistake and cause of capsize in multihulls often occurs when the boat goes from a downwind sail to an upwind one... The higher speed of a multihull often means that the change in apparent wind is far greater than it would be on a monohull in the same conditions. For example... lets say you're sailing on a dead downwind on a trimaran.

The wind is blowing 25 knots, but the boat is doing 17 knots, leaving the boat with an apparent wind of 8 knots. That same boat, turned upwind might be able to do 15 knots on a close reach, with an apparent wind of almost 38 knots—the apparent wind has over quadrupled due to the change in course. Now, unless the captain was paying attention, the boat is heavily overcanvassed and really on the borderline of capsizing.

A monohull in these same conditions, unless it is either a larger boat with a longer LOA or a planing design, would probably see 8 knots DDW with an apparent wind of 17 knots, and do 7 knots upwind, with an apparent wind of about 30 knots... or a bit less than double the previous apparent wind. Also, the monohull can heel to let the excess wind force blow off... the multihull can't.

A few good books for you to read:

Chris White's The Cruising Multihull,
Michael McMullen's Multihull Seamanship,
Thomas Firth Jones' Multihull Voyaging,

[Corsairquestions]

Wow, thanks for that extensive and great answer!!! Another bit of info- this boat did not have a wind speed indicator, but even before the wind picked up we were doing 12 - 15 kts!!!

As I suspected, among other things we were doing wrong, we were carrying too much sail, and were sheeted in too tight for the conditions. Thanks again.

[sailingdog]

Glad to help... BTW, if you want to see some trimaran sailing in relatively heavy conditions, worse than what you were out in....click HERE.

You'll notice how calm and relaxed everyone is...mainly because we're reefed for the conditions... In the video in the link, the conditions were 25-28 knots with gusts up past 35 knots... and 7-9' seas.

[Corsairquestions]

Originally Posted by sailingdog

Glad to help... BTW, if you want to see some trimaran sailing in relatively heavy conditions, worse than what you were out.

You'll notice how calm and relaxed everyone is...mainly because we're reefed for the conditions... In the video in the link, the conditions were 25-28 knots with gusts up past 35 knots... and 7-9' seas.

Nice video. Looks like only the jib is rigged. While the ocean swell is certainly larger than we experienced, the wind and white caps look to be less than we experienced. I wish his boat had an annemometer, because if you say winds were 25-28 kts in the video, we might have experienced over 30!!!

[sailingdog]

Cameras, either video or still, tend to flatten out the waves quite a bit. We were under genny alone and that particular section of video was shot on the southeast side of the Elizabeth Islands, with as we were headed down towards Menemsha, on Martha's Vineyard, so the waves there were a bit smaller than on the other side of the Elizabeth Islands, were the wind out of the Northwest had a bit more fetch.

[denby]

Dog,

You're starting to scare me, is that a bb grill behind you? Don't tell me the next thing you're going to do is buy a Catalina.

[sailingdog]

Denby-

Dogs gotta eat...and this dog likes BBQ... No catalinas in my future though.

[denby]

Ok then, but if I hear you're looking at Catalinas i go over there and slap you off the side of the head, just to bring you to your senses.

[sailingdog]

Thanks Denby... I knew I could count on you.