Off the top of my head, the list is as follows:

Lifejacket
whistle
personal strobe
charts of the area
"safety line" (tether)
EPIRB/PLB (1 per boat, although I'd prefer to have one on me at all times)
non-expired flares
compass

Additional stuff that's needed for the race as it relates to your person:
Hydration pack
powerbars
big floppy hat
plenty of sunscreen
kevlar bottom'd booties (scuba boots work well for this)
"light sticks" (those things that ravers whirl around - useful for chart reading at night)