The blanking plate I fitted last year, in replacement of the plastic flaps, over the outboard well worked well, but was quite awkward to fit. There is not much room under the outboard itself when tilted up, and the projecting cross bars I fitted to the plate to stop it going right through the hole really got in the way. They catch on everything and I had to develop a very proscribed sequence of movements to get it in and out. Not an easy thing in a seaway.
So I have removed the bars and used two strips of thin ply across the underside of the well itself. These form ledges at the front and back of the well that the plate fits against. There will be slight increase in turbulence due to these plates, but they are very thin, so I think it will be negligible. The strips actually come from the plywood covers which originally held the plastic flaps in place. They already have CopperCoat on them. It is much easier to fit the plate now, although I can't test it in anger until next season. I am not planning to go back to the flaps.