I've never really considered having a boat with "too much" horsepower but a boat meeting the purchase selection criterion I have, also just happens to have 1300+ HP. I've never had a boat with more than 550HP, this would be new to me.

What is the downside to these rigs?

Are they generally a bit more troublesome when it comes to keeping them running?, I suspect yes. Do they have a tendency to spend much more time in the shop?, I suspect yes. Do repairs in general cost a lot more?, I suspect yes. Do they burn a lot more petrol? I suspect yes.

Now, if I never use more than 1/2 of the potential horsepower does that change things (i.e. max speed is say 3K RPM)?

I'm not feeling shy about a lot of HP, I think it is better to have it and not use it than it is to need it and not have it.

drop it in a 22ft donzi and have fun

I have always said you can never have too much Horsepower. I have people asking me all the time why I have a boat with so much HP and don't use it. My answer is if I need it I have it. If you have a high HP motor and you do not run it hard it will last if put together right. I have owned my current boat for over 5 years now and I have never run it up to the max speed the previous owner and Teague says it will run.

I think all of your assumptions are on point.

If I could single out the "biggest" drawback:
-You better know someone or have access to a good high perf mechanic or engine builder, know what all the parts are and how the system works, because when things go wrong or you need to troubleshoot or check things, there's no calling in the Merc mechanic or using your local yard / marina. I really only did some of the things I did on bigger engines and setups because there is a local support system of people around me.

I own a company that builds performance engines (and not marine engines) and everyone always wants to be savage and say that there is no such thing as too much power. Its our nature to want to be the best, have the best. I think one of the biggest mistakes a customer can do is get in over their head on and engine program that is very maintenance intensive, and especially if they can't do their own maintenance and enjoy doing it. They see huge HP builds that the industry features and advertises and brags about etc....and they think that is what they want to get into.

99% of the market isn't racing competitively. What they really need and want is to pull the boat up to the ramp, have that thing fire up every time, be able to mash the throttle without shattering a drive, and not have to do a bunch of maintenance every time they put the boat on a lift. There are some good marine engines out there that if you get them big enough can offer huge power and some reliability that will more than satisfy your competitive spirit, and I think with turbos being used now that this will extend the reliability and power output even further.

That was wordy....get something you can maintain and enjoy. Buy engines from reputable engine builders...even if it takes a little longer to save for. There are engine builders, and there are engine assemblers...know the difference.

Have u asked your insurance agent the difference between a 500 up boat and a 1300 hp boat?

I have always maintained is to put the largest horsepower you can afford to use and maintain and then conservatively use it. The engine doesn't work as hard as a smaller HP wot all the time. We have been blessed with a 7.4 mpi and while I'll admit I've burned the carbon out a few times we usually are in the mid rpm range cruising. A little easier on the gas consumption too.

3pointstar

hmm, I have not asked my insurance man...I should do that asap though...Thanks!

Is it implied that high powered boats crash more often than your family cruizer driven by wannabe "captain dad" who has every cup holder on the boat filled with an adult beverage?

To me, "captain dad" can be equated with a teenage auto driver vs. a knowledgable and skilled enthusiast. Some of the very best auto drivers I know are enthusiasts driving high performance autos. They/we pay $$$ generally because of the auto value (which I guess to some degree indirectly relates to HP).

I wonder what formula's Insurers use?

1) HP/ft length - higher score = higher risk
2) HP/weight - higher score = higher risk
3) HP/IQ - lower score =higher risk
4) HP/owner's latitude - lower score =higher risk

I will only add this: I have a buddy who had a fountain, and years ago won the loto several times. I would tell him he needs to soften up his tune and enjoy the lake, however, all summer long, he'd keep that thing maxxed out on edge, because he said, "What if someone comes along and outruns me and I have a couple of hundred horses in the bank I didn't use?". I get it, but.....

Paranoia aside, rarely would anyone have the opportunity to outrun him, because one or both of the engines was ALWAYS having some issue that kept him off the lake 85% of the summer. Even when he was on the lake, we were butts-up in it finding a noise or checking something worrying if it was going to go south.

My philosophy is make as much horsepower as you can afford to make reliably. Two passes and you're done isn't my idea of fun (anymore) There will ALWAYS be someone faster!

It's too much HP when it spends more time in the shop then on the water.