How could they prove that you knowingly exceeded the HP capacity? Also on a boat greater than 20' like you said there is no legal max HP regulations which I believe is the case here.Look, I'm not going to argue/debate with you. I will say this, in the event you are in a serious boating/vehicular accident and it ends up in court you might well be shocked what you see and hear...
In the event of a serious boating accident the utilization of an "overpowered" boat is a pretty serious piece of evidence supporting the irresponsible operation of said boat. It won't matter if I'm the plaintiff or the defendant.
Secondly, why do YOU think most credible insurance companies (Probably ALL) REFUSE to cover boats if the engine exceeds the max hp rating (or in violation of any regulation/law)? It's because they are EXTREMELY risk averse AND have suffered serious losses in regards to these EXACT circumstances. Jury's aren't normally partial to insurance companies or "irresponsible boat operators." Ths is especially true if the operation of the car/boat/plane by the plaintiff/defendant is deemed to be irresponsible and contributed to serious bodily harm or death of an innocent.
I'm sure you'd agree with me that 25hp is TECHNICALLY no big deal, but, to a lawyer it is a significant piece of evidence of irresponsible behavior. It's especially significant if it was operated while KNOWINGLY in violation. They'll pound that into a jury along with anything else they can utilize/"twist" to demonstrate fault by either party.....plaintiff or defendent.....civil or criminal.
Btw, I'm no big fan of either insurance companies, a lot of lawyers, or of our legal system in it's present form. However, I'm a realist and reasonably well informed so I choose to adhere to all laws and regulations, even if I think they are ridiculous.
Example: A 20.000001' boat is exempt from hp regulations but a 19.999999' boat isn't? I'll promise you this, in the event of a serious boating accident resulting in litigation BOTH litigators will KNOW the EXACT length of the boats involved, their power plants, any and all laws/regulations involved with both, and how that information might have contributed to the event.....and they'll use that information at trial if they think it might well bolster their case.