Downwind Gusts

Originally posted by winging it

Hi, 
this is going to sound totally counter intuitive, but give it a try:-

Assume you're on a nearly dead run (jib won't  goose-wing without jib stick).
When a gust hits you, the centre of effort of the mainsail is offset to the hull and the boat will try to gripe up into the wind. 
As the boat does this, it heels to leeward and the rudder blade lifts out of the water. The hull shape of the boat will accelerate the turning into the wind, and the boom will hit the water, locking the mainsail and you'll blow in.

It's often linked with a rolling moment.

In this situation
1) run to the transom - keep the bows out of the water at all costs.
2) try to keep the boom out of the water by sitting out.
3) DON'T try to turn downwind - if you do, the heeling force will diminish rapidy, the rudder will suddenly bite and you'll roll in to windward....Just keep a firm hand on the tiller.

If you sail with the boat heeled to windward, then you move the centre of effort (from the mainsail) over the centre of the boat. This means that there is much less force trying to turn the boat into the wind.
It feels horrible (keep a bit more plate down) but is actually more stable than trying to keep the boat upright! As a gust hits you, balance carefully, and use only small rudder movements - you will steer the boat better by changing the heel angle!

Look at the Lasers, Europes etc - downwind they heel so that the mast is well off vertical.

In this configuration, when a gust hits, you can actually adjust the heel by using the rudder (small amounts!).

If it's at all possible, buy a jib-stick and get it in as soon as possible downwind. It really makes a lot of difference to the stability when a gust hits from astern.
(based on an Enterprise with F6+ gusts - no jibstick = swim, jibstick = screamer)

Colin