Oday Tempest rudder

[groundhog]

Walking in my marina last weekend, I noticed a small sailboat, an Oday Tempest I believe.

The rudder had horizontal wings extending on either side. Seems a good idea. I guess it helps tame the pitching motion?

Why dont more boats employ this?
gh

[BigZ]

If the wings are at the base the intent might be to control turbulence rather than pitching. You’d have to do some research into the use of wings on keels for a more in-depth explanation. I’d guess what you see is an owner-applied change, not as manufactured.

Why don’t others do it? If it had some real, measurable benefit I’m sure others would.