> I currently kayak, 6mph for 4 hours, 6mph for 8 hours. With a
> racing boat I might be competitive.

The fastest times by a single in this race's 20+ year history, were just under 9 hours, about 8hours 52 minutes. I think they must have had the run-off tide at the right time. That means they would average about 8miles an hour for the entire race.

And no, I'm not planing on winning, finishing would be nice tho.