Capsize

Moderator: GreenLake

Capsize

Postby Rakozy » Sat Sep 19, 2015 6:25 am

I'm happily sailing along with my mast laid over to the port side. I realize that I am at the limits of my boat and she is about to capsize. (My first reaction is to release the main sheet to reduce power).

Question:
Can I quickly change course (steer out of the situation) by turning to port or starboard?
(Turn port or starboard) Which is the best direction to reduce the chances of taking a swim?

Rakozy
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Re: Capsize

Postby K.C. Walker » Sat Sep 19, 2015 10:39 am

Your immediate reaction is the correct one, sheet out! I am a fan of using ratchet blocks and not cleating the mainsheet when conditions are a bit dicey. I enjoy high wind sailing so I do this quite a bit. If you can reduce power by using your sheet, it doesn't take but a fraction of a second, you may not even need to change course (which is way slower). Hiking out is the next part of the formula. I use hiking straps and highly recommend them. Also, sailing gloves help. So the mantra of fast sailing and also in control sailing in a centerboard boat is… Ease… Hike… Trim.

So your question as to which direction to steer should be upwind or downwind. And that depends on what point of sail you are on.

For close hauled you ease the sheet and the boat starts to come up on its feet a little bit which gives you the chance to hike out harder which then brings the boat on its feet a little more, often enough to be able to trim back in while slightly heading up. If you are still overpowered repeat the cycle. If you are still overpowered you may need to reduce the power of your sails. You might want to reef or you might be able to de-power by cranking the out haul full on, the vang full on, and possibly Cunningham.


Now, if you are on a beam reach you can head either down or up to reduce power (still using the sheeting first). If you are below a beam reach you definitely want to head down wind to reduce power. If you head up then you actually go through a more intense power band as you go through the beam reach. You often have to ease the main sheet a tad to be able to get the boat to turn down if it's really on the edge (so the rudder can get a bite). This is a little counterintuitive for beginning sailors but it's really fun. If you're in a good high wind situations and you've got reasonable control over the boat and you turn down in a gust this is often where the boat picks up and planes which actually improves control (and is a thrill). If you turn further down the boat will slow considerably. The concept is to steer the boat under the sail plan to bring it back up.
KC Walker, DS 1 #7002
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Re: Capsize

Postby jeadstx » Sun Sep 20, 2015 12:08 am

+1 for what K.C. Walker said.

I always sail with my main sheet in my hand to be able to release it to de-power if the need arises. Yes, sailing gloves are helpful.

John
1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
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Re: Capsize

Postby GreenLake » Sun Sep 20, 2015 4:42 am

Ratchet blocks!

As I've mentioned here before, I like the Ronstan ones, because they hold better (not only my impression, but according to a test the ratio is something like 2:1 to the nearest competitor). And, their auto setting is just about perfect for me. Set it and forget it. Disengages the ratchet when the line goes slack (and in light airs).

I have an older Harken on another boat, and I don't like it as much. The selector (on/off) is much easier to use, but you have to use it, because you don't want it on in light airs. One more thing to think about.

In some conditions, the DS will violently round up instead of capsize. It feels like it's twisting out from underneath the wind. I haven't quite worked out when that happens, but I think several things are involved. First, the boat heals to the gunwhales. The rudder loses grip, but several forces steer the boat upwind. One is the fact that the center of effort for the sails is aft of the center of lateral resistance (or a bit aft of the CB), the other is that, when heeled,the hull shape will add a turning moment.

If a gust comes from the right direction, these forces combine to turn the boat, rather than capsize it. What the "right direction" is, I haven't been able to work out, because when this happens, it's usually quite disorienting. One moment you think you are going to go over, the next moment you are headed into the wind, after some giant hand "twisted" the boat from underneath you. The only useful observation I can add is that the few times this has happened to me was on lakes that had hills or tall structures nearby, which usually means that gusts can bring more of a windshift than usual.

But still, would be nice to know what the conditions are that cause this instead of a capsize. Anyone know?
~ green ~ lake ~ ~
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Re: Capsize

Postby Rakozy » Sun Sep 20, 2015 6:16 am

My thanks for sharing three EXCELLENT explanations! Really good stuff.

Bill Rakozy
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Re: Capsize

Postby Interim » Tue Sep 22, 2015 8:40 am

We get laid over quite a bit on our inland lakes, especially in the Spring. Gusty winds and changing directions make you stay on your toes (if they're not hooked under hiking straps).

+2 on holding the mainsheet in your hand in such conditions.

As the boat goes over, you are reducing the sail exposure to the wind (which depowers the boat a bit). However, as GreenLake noted, this will also push the bow to windward. With a little weather helm, you can go even farther to wind. The danger here from my experience is that in shifting winds a roundup can result in coming about in an unplanned way. With the backwinded jib and the moveable ballast on the wrong side, you can go over easily.

--john
1979 DSII
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