Hydrofoil

[chris]

Need info on hydrofoils. How much did it help? Did it reduce planing speed? Did you lose top speed? Was it worth it? Thanks.

[freyedknot]

hydrofoils are fine , i have one on my boat to fix the porpoising due to al the wght in the rear. but i jst ordered a happy troller troling plate today to also bring my troling speed down.

[ETT]

If you're considering a hydrofoil, you should look at Smart Tabs. www.nauticusinc.com.

For all the reasons you mentioned.

[LochNessMaster]

Don't have one on my present boat (Ranger 681VS with a 115) but did have one on my previous boat(Sea Nymph 16" w/ 40 hp).

The Sea Nymph was a very light boat. I felt the hydrofoil helped it ride a little better in rough water. I also felt it got on a plane faster. The stern definitely didn't dig in as much when I started out either.

I don't know any of this applies to all boats. They're mostly opinions I hold based on my experience with a boat and motor combination. Haven't put a hydrofoil on my Ranger because I haven't felt the need for one.

Generally, I think a foil helps the ride more on a tin boat because they're lighter, and because of their hull design they're more apt to go up and over a wave rather than cut through it. For the same reasons they might help an aluminum boat get on plane quicker. While a foil may help the ride and getting on a plane the price paid will be more stress on the transom.

Hope this is of some help.

Craig

[Basscat]

Chris: I had a hydrafoil on my 20 ft. deep Vee, center console, heavy boat. It gave better hole shot and rode higher at lower speeds but I didn't notice any changes otherwise, including top speed. I removed it because at medium speeds it made the boat "tilt" to the driver's side. I understand this is a common occurrence. If you are having a problem, there is a guy near Houston who custom makes a foil that does give a better hole shot and medium cruising speed. Problem is you would have to take your boat to him. LMK if you want his address. The cost is about $250.

[glb]

Advantages of a fin:

1. Faster getting on plane.
2. Plane at a slower speed.
3. Less bow rise getting on plane.
4. Better visibility at slow planing speeds because the bow is lower.
5. Better fuel efficiency at most planing speeds if operator trims drive up when possible. This is because the prop is more efficient when the prop shaft is closer to being parallel with the path of the boat rather than pointing at the bottom of the lake behind the boat.


Disadvantages of a fin:

1. Gotta drill holes in the antiventilation plate to install fin.
2. Warranty may be affected/installation may cause additional forces that could damage the lower unit (But not likely)
3. Handling characteristics will be affected.
a. with down trim while at cruise speed, it is common for the boat to lean to one side or the other.
b. with down trim at cruise speed, it is common for the boat to lean more in a turn than without a fin. (sometimes to the point of putting the rub strip or gunwhale in the water.)
4. in some cases top speed may be affected. This is usually less than 2mph, if there is any change at all.

To explain the handling characteristics, remember that the fin is trying to lift the stern of the boat. This causes the stern of the boat to be supported by the fin and one side of the hull. The fin is simply too narrow to balance the boat, so it leans. This same condition is present in a turn. The boat will lean into a turn more, but the turning radius will be larger. This can get to the point of being somewhere between uncomfortable and scary.

Hope this helps.