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How to handle a gust upwind

Posted By: Leo Ambtman

How to handle a gust upwind - 10/01/12 07:34 PM

What is the best way to react to a gust when in trapeze? First wait till the gust hits you. Than give sheet. Accelerate. Than steer up a little. Than tighten the sheet. After the gust steer down a little. Than give sheet or hold sheet? Some people steer up just before the gust hits. Is that wise? Sometimes with a too flat sail and tight sheet the boat feels dead. Why?
Posted By: Tornado

Re: How to handle a gust upwind - 10/01/12 10:19 PM

you didn't mention the boat but I will assume you have a modern prebend mast.

Start off in light air with downhaul at just enough tension to take wrinkles out of the main. Once you are able to double trap and have the boat popping up too quickly, begin inching on some down haul to control the power. Once you're in the ball park, have crew play the main while trapping to fine tune the power during the gust. The goal is to ease at gust onset and then start sheeting in again BEFORE the lifting hull reaches its max height & starts to fall. You want to keep the hull off the water. If the crew is needing the sheet more than an easy arm length of line to control the hull pop...you need a bit more DH. If the hull stops lifting/boat feels dead...you've got too mcuh DH for current breeze.
Steering up to control the power is not a go fast technique...but it can save your butt is an emergency (ie if crew forgets to react on the sheet).

This technique will make the boat feel like it is on rails...no longer popping up rapidly...squirting forward in the gusts. It need practise, but when you get it right the rewards are big.

Posted By: Mark Schneider

Re: How to handle a gust upwind - 10/02/12 04:25 AM

goal is to ease at gust onset

This is the key skill.... you need to see the gust coming at you.... Your sheet hand must anticipate the gust hitting your boat and ease at exactly the right time .... if you are counting on feeling the hull lift from where you are normally flying it... you are too late... the elevator ride up and down is not fast.

The fast boats don't change the boat attitude.... they go faster in the puffs... the ease at the onset and the sheet back in as the puff attenuates gives you the speed.

Another gear is to take height.

you take height if that is called for tactically. That conversation height or speed also needs to happen before the gust hits. it also requires seeing and anticipating the gust... not feeling the gust.
Posted By: brucat

Re: How to handle a gust upwind - 10/02/12 04:37 AM

Hard to perfect, but if you can work the traveler rather than the sheet, that's even better.

Mike
Posted By: Jake

Re: How to handle a gust upwind - 10/02/12 12:24 PM

Originally Posted by brucat
Hard to perfect, but if you can work the traveler rather than the sheet, that's even better.

Mike


I'm not sure about that with a square head sail plan. We only ease the traveler as a gross adjustment after the downhaul is maxed.
Posted By: brucat

Re: How to handle a gust upwind - 10/02/12 01:37 PM

I said work the traveler (as in, treat it like a sheet), not ease it as a gross adjustment.

I'm not capable of it (or skilled at it) either, but apparently it works well for some teams at the upper echelons of Hobie 16s. Crew holds the main sheet, skipper pumps the traveler. Keeps the boat flat, and more importantly fast, as you're not dumping wind out of the sail, but squeezing it out the back.

There are very few American teams that actually do this, however. May just be that we don't practice or race in enough wind consistently?

Mike
Posted By: carlbohannon

Re: How to handle a gust upwind - 10/02/12 02:09 PM

Originally Posted by brucat
Hard to perfect, but if you can work the traveler rather than the sheet, that's even better.
Mike


This is somewhat boat and sail specific. It can work on a H16 but on other boats, you go slower. The Tornado does not like it. On some boomless boats having the crew work the downhaul with the skipper ready on the main in case the downhaul. bottoms out, seems to work in heavy air. On a lot boats, you need to foot off a little(why you may need to do this is related to apparent wind and is left as an exercise for the student)


Also, these techniques assume that you have good sails and everything else is set right. Have you ever had the downhaul hang up full on and discovered that nothing seems to work right. Or put new sails on your boats and found out you had been heading up rather than easing out to compensate for the blown sail?
Posted By: Jake

Re: How to handle a gust upwind - 10/02/12 02:13 PM

Originally Posted by brucat
I said work the traveler (as in, treat it like a sheet), not ease it as a gross adjustment.

I'm not capable of it (or skilled at it) either, but apparently it works well for some teams at the upper echelons of Hobie 16s....

Mike


i.e. not a square head sail plan...you've got so much sail area up high with a square head that you're much better off to make shape changes up high. The traveler reduces the angle of the entire mainsail resulting in a substantial loss in power. Tiny changes to the traveler make big changes in the power level on a square head and is very hard to control...best to drop the power up high by inducing twist with downhaul and mainsheet tension while keeping the bottom of the sail driving lowering the center of effort and reducing the healing force. Drop the traveler an inch at a time so you can still work the puffs with full-on hard mainsheet in the lulls to maintain as little aero drag as possible.
Posted By: brucat

Re: How to handle a gust upwind - 10/02/12 02:20 PM

Right. Well, I didn't see where he said he had a square head either...

Good discussion points to point out the key differences, Jake.

Mike
Posted By: Leo Ambtman

Re: How to handle a gust upwind - 10/02/12 02:49 PM

I sail a Tornado with a square head. I agree with Mike and Mark about the best way. As the true wind increases, the apparent wind will veer, so you could steer up a little. At the other side you have to give the boat time to accelerate and the apparent wind will veer back. I think the best way is to give sheet, however a too much twisted sail is less effective. The jib may be crucial. With the traveller you close the gap. But even on a A-cat they will use the sheet in a gust. So probably twisting off is not so harmful.
Posted By: Jake

Re: How to handle a gust upwind - 10/02/12 04:49 PM

Originally Posted by brucat
Right. Well, I didn't see where he said he had a square head either...

Good discussion points to point out the key differences, Jake.

Mike


Good point - I recalled he posted about a Tornado previously.
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