Coast Guard....
The coast guard has a mandate with the pwc manafacturers that no watercraft be built to exceed 70 mph......but, anyone can purchase "mods" from a high performance shop and exceed that limit. This is normally done for racing. If you mod for local recreation, it doesn't mean you can't get a ticket, you can. The Marine Reasources (water police) can issue you a citation for reckless endangerment.
Then, on the other hand, your engine as built may last 10 years or more. When you mod, you dramactically reduce the engines life cycle. Just the other day, I saw someone looking for a new set of exhaust valves for his 1503. That was why to early to be doing that kind of work on such a new engine.
But hey, this is a free country, do what you like.....its your money and your life.