AJEaster said..
On your GPS sails, I would recommend that you head straight to the shallow water on the mud bank and add some more downhaul - perhaps 1cm+, but not so much that it kills the sail profile........you will know by the feel of the sail when it is too much downhaul as it will feel lifeless and twitchy
Other things that I do which I find work for me and may be worthy of consideration:
# I carry a smaller fin and screw driver in my camelpak, esp when the wind is forecasted to increase during the day. Dropping in a smaller fin will help to settle the board in stronger wind.
# Lower your boom 2-4cm as it gives additional leverage. I find this makes a big difference.
# You will find that the best days for GPS are when you are well overpowered going upwind or across the wind, which means you are really lit up going downwind. To help get upwind or across the wind with more grace when overpowered, increase your outhaul a few cm which flattens the front profile of the sail, then release again going downwind. An adjustable outhaul system is relatively cheap, and it will make this easy to do whilst sailing.
# Also with the above point, when going upwind or across the wind, sit down harder in your harness (seat harness) and lean fwd more into a traditional racing stance (watch Mark Jordan sail - he is the master of this) which will put more weight on the mastfoot and commit you to forward motion and stop the board from flying too high off the fin. Also having the front hand further forward on the boom in extreme gusts helps with confidence when you need to push with your front hand to stop the sail from slamming you into the water on the windward side of the board.......then when you slingshot to head downwind, bring your front hand back and smile because you are in for a good fast ride.
In saying all of the above, if you are getting slammed left, right and centre, it is not fun, and it is fatiguing and dangerous, so in that situation there is no substitute for smaller gear. Hope that helps Phil.
I do that.

.I was thinking it was a bad habit I needed to get out of but it feels much safer on days like yesterday..