turn fins on a mono

[bwells]

When installing turn fins on a mono hull, should they be perpendicular to the hull? What I mean is perpendicular to the V. I assume the reason is that the outside fin would be out of the water while the inside one is doing the work. Also, is there a general rule on the depth, like 1/4 inch less than the keel at the transom? Thanks

[m4a1usr]

All of my V hulls have no turn fin in the water on plane. Its added drag and does nothing to stabilize the hull while going in a straight line. My rule of thumb is its needed in a turn and nowhere else. Now where to set them depends on how much clearence the hull has and if you are suffering any effects from the transom spinning out during a turn. Its safe to say that each turn fin should be 90 degrees from the angle but alot depends on stability too. This might require a slight modification to that assumption. I like mine mounted as far out as possible but opinions vary so let the commentary decide. Stability is the issue so as speeds increase so does the importance of location.

John

[bwells]

OK, good to know I'm on the right track. Thanks for the input!

[Bill-SOCAL]

Mono turn fins are installed at 90 degrees to the bottom of the boat.

[bwells]

Thanks Bill. I saw the transom of an SV27 and they appeared to be kicked outward even more but I will do the 90 degree thing. This boat is not a speed demon but just trying to make it not spin out and turn a little sharper.

[Bill-SOCAL]

Here are a couple of photos of a couple of my boats

[Efis]

Is that a shaft saver on your antennae tube?

Blake