Thanks for the links. I would add the following to your gear.
Flashing strobe light:http://www.boatersland.com/acr3959.html
And consider a higher output radio as in rough windy conditions you need more power to get a good transmission. Uniden and Icon make a small compact radio that is 5 watts I believe. I bet most kiters don't even know you can hail the coast guard and other boaters on channel 16.
I had a small combination waterproof strobe/flashlight as well that I left out of the list. I got it years ago as a masthead light for nighttime windsurfing. If you are in the water after dark a strobe can be a great locator and longer lasting than flares.
More at: http://www.rei.com/online/store/Product ... rn=4501499
In the Crossing, IF seas were up as can easily happen with slightly strong northerly winds, say 8 to 10 to 12 ft. plus, if your kite were down I imagine you would vanish from view within a 100 m or less from the smaller chase boats that were in use. I imagine they wouldn't be able to hear you even with a whistle at such a range either with the noise of the running sea.
You are miles offshore between the USA and another country drifting north at 3 to 4 knots. The sun sets at 5:30 pm. We kiteboard to have fun, not to set ourselves up for a fairly easily avoidable death. At least I hope so.
Not a lot of guys ride 60 plus miles from shore. Still, I routinely go a mile, sometimes a few from shore. If something goes wrong, the kite goes down and I can't swim in as I have in the past, then what? I haven't been carrying more than a whistle for years. Still, I have "thought" many times that I "should" be carrying some effective signalling stuff. Got it now and the lot fits into a small pouch that is on a belt on my back out of sight and mind.
We have hundreds of miles of coast here generally with landable beaches. Some guys ride off of islands, in inlets and other areas with adverse currents, wx, rocky shores, etc.. There have been stories of guys being swept out of inlets, disabled until after dark, being swept off island (I almost had this happen to me a mile off of Antigua a couple of summers ago with a messed up kite on the water).
If you hug the shoreline, (threatening our access in some areas), avoid funky currents, islands, rocky shores, etc. you may not have need of signalling gear. Some guys are exposed to these hazards more routinely. It is something to consider, BEFORE you need it.