So what do I conclude from all the feedback? How can I avoid further occurrences of the dreaded death grip cramp.
For sure, dehydration can be a cause of cramps, not to mention all sorts of other bad things. But I'm pretty certain that dehydration wasn't the cause on this particular day. I had drunk a fair amount of water at home before leaving for the regatta and another couple of bottles while rigging. And, without need to get too graphic about the details, I did use the same test that the US Olympic Sailing Team used in Beijing to make sure I wasn't dehydrated.
Depending on which source you believe, low sodium, potassium, calcium or magnesium in the bloodstream can also be a cause of cramps. One sailor at the regatta told me that he used to have exactly the same symptoms as me, but when he changed to drinking Gatorade rather than water to hydrate before and during the racing, his cramps went away. His theory was that drinking only water "flushed" the essential minerals from his system. Gatorade contains sodium and potassium, so if shortages of these are the cause of cramps, it could well be the cure.
The wise old man of Lake Eustis, Sam Chapin asked, "Do you think you have a death grip on tiller or maybe on the sheet. Try practice with concentrating on letting the ratchet block hold the sheet after you get it pulled in and just a light grip in the tiller?" Ahah. I think he may be right. I do tend to hold the sheet way too tightly, and also to use my sheet arm to support part of my weight when hiking. When I'm excited about doing well in a race I tend to try even harder and hike even harder and pull the sheet even harder. I'm fairly certain that this was a contributing factor on this occasion. I must learn to let the ratchet block do the work and not tense up my forearm muscles too much.
Of course, as this was the first time I'd raced in a real Laser regatta for many months, my forearm muscles were probably a bit out of shape and so it was easy to over-exert them. I suspect that some simple exercises in the off-season to strengthen my grip and forearms might have helped avoid the problem, and that now I'm sailing more regularly my arms and hands will become strong enough again that I won't work them too hard during normal racing. At least, I hope so.
Summing up the Tillerman method for avoiding death grip cramps...
1. Drink the right stuff.
2. Sail more.
Sounds good to me.