The "gate" is awfully tough to control at an offshore race. Plus, people have been conditioned to not paying admission, for the most part, to offshore races for many years. Charging for something you've given away forever is the toughest of tough sells.
I believe APBA Offshore, back in 2000 at the Key Worlds, enabled spectators to get a day pass on a cruise ship to watch the races. Not sure how that went, but it seemed like a good idea. I do know that there were plenty of cruise ship passengers watched the Norwegian UIM Class 1 Grand Prix from their ship in Oslo Harbor a few years back, because I was there to cover it.
The idea of a floating grandstand, though not new, remains intriguing.
My point about Asif Rangoonwalla and the two-class field in P1:
I. He can afford to "lose" racers when they get unhappy because, frankly, he has the bank roll to do that. And some of his racers have seriously big bucks. In short, his circuit managment is not beholding in any way to any racer. If they don't like a ruling or a rule, they can walk. A well-heeled autocratic ruler can be a good thing in offshore racing because he can make decisions independently (like NASCAR's France family) of his constituency. Otherwise, the inmates run the asylum.
2. Two classes are easy to understand, even for the rookie fan. You could explain P1's Super Sport and Evolution classes in one sentence each.