This is overall IMO a good idea..I like it. The sprint boat guys may be a good place to start, they are always looking for ways to promote the sport and they sort of already have a "closed course" venue. May be able to pick their brains and get an idea of how to get started.
The biggest problem I see is "yellows" legend cars are a lot different than a boat, in way more ways than one, fueling in the water, no matter what fuel your using will not fly at most locations, especially in Cali. Also this type of racing at any length will have longevity issues, spec motors or not, there is a "crate motor" class in the Whitewater Marathon game, both a BB and a SB class, you would think the boats would be pretty closely matched, but the opposite is true, you would have to moniter/police this very hard, that takes many people to accomplish, so the dedication level would have to be very high.
I would love to see something like this take off, but honestly right now given the state of the economy and your main sponsor base being on the verge of bancruptcy, I would not hold my breath, hell even NASCAR is hurting financially..
Good luck!
GT