I have an old Mastercraft inboard ski boat that I need some help with
fixing. Where the shaft of the prop goes through the hull there is a
metal plate. The edges around the plate were leaking and it was
sealed with silicon. I cut out the gobs of silicon that were there
and found that the plate sits in a 1/2 inch trough in the fiberglass
hull. When the silicon was removed I can move the plate fairly easily
by hand, even lifting it up slightly. I replaced the existing silicon
with Goo marine sealant. I let the sealant set for 24 hours then
lowered the boat back in the water. My little leak turned into a
gusher.

How is this plate supposed to be secured to the boat? Do I just need
to do a better job with silicone? Is there some adjustment that needs
to be made to hold the plate on better? Should this have done over
with fiber glass?

I put photos of the plate and problem area he www.lyonsland.com/BoatLeak

Thanks for any help.

--Mike