Hydrofoils: Will they increase boat performance?

[OliverNBPT]

18' Tripp Angler CC, 70hp Johnson, Approx 2800 lbs fully loaded. Performance is okay with two guys, three okay, four requires running on nearly wide open throttle.

Obviously not a fast boat to begin with but will consider anything that will help with overall performance.

[fishsmith]

Oliver are these the fins that slip on right above the prop? If so I didn't see a big difference with them, we had an 18ft runabout w/90hp that I used to ski off of, we added one of these to see if it would help the boat come to plane quicker, it helped a bit but very little. The advice we got was to get more horses not a plastic fin. I have the fin on my motor a 75hp, and my boat is slow to plane and then just slow with 3 people, but it's only a 3cyl so it does what it can.
They're easy to install, but you've got to put the dreaded drill to the motor to anchor them in.

[OliverNBPT]

Those are the ones, and yes, unfortunately you need to drill holes. I also have a 3 cylinder two stroke, unfortunately more HP isn't an option at this time.

When you say 'it helped a little', did it help enough to justify the $50 expenditure or is it even worth it?

Thanks for the insight.

[fishsmith]

That 18footer was 14 years ago, so thats thousands of beers and blackouts ago, but if memory serves me correct, we ended up taking it off the motor because we kept cutting ourselves on it getting in the boat / or did I break it using it as a step? anyhow the little holes didn't degrade the performance any once it was off. If your motor is older and you already bought the fins, give it a shot, if its newer an you might unload soon leave it be.
Good Luck.

[kenP]

Oliver,

I put the Dolfins brand fins on my 15' Key West with a 50 yammie and they did improve performance in the following ways: i) the boat does not porpuse nearly as much and takes small wakes much better and 2) the boat gets on plane much quicker and stays on plane at lower RPMs. As for impact on speed and fuel, if there is any I cant tell. Overall the investment was well worth it.

[179]

Waste of money, they won't affect the performance. You might want to spend a few more dollars and get an inexpensive set of trim tabs....I think Nauticus manufactures them...

[OliverNBPT]

I should be clear, I'm not looking for increased speed or fuel consumption (although both would be welcome), my goal is to keep the boat on plane at lower rpm's.

179: That's an emphatic response, I'm assuming you have had personal experience with these. Since trim tabs and hydrofoils are designed with the same objectives in mind and the hydrofoil will not increase performance, should I expect trim tabs to?

Maybe the only real answer is to increase hp which isn't an option, I'd consider an investment in either the hydrofoil or trim tabs if there is a good chance that performance will increase as defined above. Otherwise I'm the guy running wide open throttle to stay on plane with my over weight friends being upset because it took 20 minutes longer to get where we needed to be - - Mind you, I won't get gas money from any of them.

Thanks, and appreciate any further insight or guidance on this subject.

Oliver

[179]

Oliver,
To answer your question is yes, I have used the hydro-foils on two differant motors. The first was a 15hp on a small aluminum boat, the second was a 115hp on a 18' boat. In both cases I did not notice any change in the way the boat performed whether it be in stability or performance to plane. I actually think the foils caused the boat to be a bit unpredictable in sharp turns.

The hydro-foils may work on your combination but they did not on the two mentioned above. If you are looking for overall performance increase I would say tabs are your best bet, or maybe repower with a 90-115hp motor. Best of luck, let us know how you make out........

[OliverNBPT]

Okay, doesn't seem to be a strong enough verdict for me to start drilling.

Thanks for all the responses.

Oliver