Fin Or No Fin?

[tntitans21399]

I have read different things about the fins you can add to your boat but I don't see them on a lot of boats. Is it better without the fin?

[slonezp]

A lot of times "fins" are added to resolve other problems. I might use it as a last resort if I couldn't resolve the issues by changing motor height, adding or removing vent plugs to the prop, changing props,  redistributing the weight, etc,. 

[Wayne P.]

I used to have it on one of my fiberglass bass boats. I only put it on for quick planning in shallow tidal waters.

I used the Attwood "gull wing" model so there was no drag when on plane.

[Way2slow]

They improve hole shot, by help keeping the bow down and providing stern lift. They also help under powered boats get on plane. They can also help with prop issues when you have one that wants to blow out (start cavitateing badly) just as the boats starts to lay over coming on plane.

Proper engine height is critical when using one, and the style being used needs to match the type boat it's going on. If the engine height is not right, (too low) it will create extra drag and slow you down. The big whale tale looking things do fine on slower boats but on some of the faster boats can be dangerous when turning. They can bite into the water can cause the boat to do all kinds of bad things.

I run them on my hotrod motors but only use the SE Sport 300 because of their narrower design. It's no fun at all to be making a 70mph turn (and that is after slowing down) and have one of those things bite into the water. When you slam 325hp on the back of a 20ft boat, it wants to rare up pretty good and they work great at getting it to "launch" out of the hole. I think the main reason you don't see many of them, they are too ungodly ugly and dorky looking to use when not really needed.

[Scott F]

I've got one on my boat. I have a 75 hp motor on a boat rated for up to 115 hp. It helps me get on plane much faster and stay on plane at much lower RPMs. I do lose a little bit of top end speed which I never even notice because I almost never run wide open anyway. It has saved me a lot of money on fuel over the years. The fin was a lot cheaper than the thousands it would cost for a bigger motor.

[WIGuide]

Fins are usually associated with an under powered or poorly performing boat. Looking at the packaging they'll promise to do just about everything short of turning your boat into a drag racing boat. In certain situations they can help with attributes other than getting on plane quicker, but that's usually about all they're good for. 

[zachb34]

Not trying to hijack the post but will they do anything for top speed? Is it worth putting on something as small as 15 horsepower? I have one just don't know if I should use it or sell it.

[Way2slow]

With the motor set up to it's proper height, a hydrofoil should have no affect on speed. If the motor is set down too low, then the hydrofoil will create drag and slow you down some. Stern heavy and under powered boats get the most benefit from a foil. They provide extra lit at the stern, getting the boat on plane better and keeping the bow down. Even on a jon with tiller, when you are alone, sitting in the rear and the bow raises way up starting off, the foil be help keep the boat down.

[J Francho]

I have an aluminum foil on my Pro Max. It's only for the hole shot. It's not in the water when I'm on plane.

[Way2slow]

The "Allison" foil works great on Bullets, which sounds like what you have. The SE Sports work good also. On high performance boats, like the Bullet, sometimes you need to trim about an inch or so off each side to make sure it doesn't bite the water.

[J Francho]

Call me crazy, but I think mine helps me come off plane better. The stern sinks first, but don't get that bow to the sky thing I see other boats do. Maybe it's just the hull design?