Funny, I just got my Wilderness First Aid Instr cert and this came up. Basically: stay low, out of caves or outcroppings, away from trees and hope for the best. Also- stay spaced out from one another instead of bunching up in a group.
Finally, a wet boat is not an insulator. Wet is wet and if the water is hit near you - you will get zapped.
But if you hear banjo music- then by all means- paddle faster!