> This weekend I am
> going to measure him for how high he will need to be (I expect it to be
> between 3 and 4 inches.) I will use half-inch plywood bonded in an
> inverted 'U' to raise him up. .

While you are at it, put in a block of cheap styrofoam under that seat. You can hot glue it to the underside of the seat so it won't be sitting in the bilge water, and it will add a bit of built in flotation. Make it big enough so that if the glue comes loose the block can't fall out.

Juat a thought.

Paul G. Jacobson