20MA Trim Tabs

[Bushwacker]

STE, I think you have the tabs upside down in those pics! No benefit to having the ends turned up. That will let water escape out the sides and reduce lift! The old Bennett tabs I put on my Seafari had the ends turned down 90 degrees to prevent water from escaping out the sides. Result would be similar on your tabs if you flipped ‘em over!

As for mounting location, I’d put ‘em all the way at outboard edge and trim the mount flange as required. I used the tabs mostly for roll control. (Deep V’s tend to lean into the wind. In a short steep chop, rolling the boat AWAY from the wind and waves increases the deadrise relative to the waves, providing a significant improvement in ride!) Outboard tabs will give maximum rolling moment for a given amount of tab deflection. More deflection = more drag, so you want to minimize that!

I believe the mounting instructions said to mount the tabs about 1/8” above hull surface. If the tabs are wide enough that the inboard edge is inboard of the outer step, several inches of the tab may be out pf the water when on plane and not doing much. However if you invert them relative to your picture, the resulting concave shape will trap water and may eliminate that problem.