I would be worried ...if you just plug the top of the hole. Getting something on the outside of the hull would be important to me.......
Thanks - but I'm ONLY interested in working on this from the outside of the hull. On the inside, I have a plug where the engine mount is going to be reinstalled.
I'm going to dive down tomorrow or Wednesday and attempt to insert a bolt with washers (if the curvature of the hull at this location permits), and bond it with some type of underwater-curing epoxy.
Unless better alternatives are presented here.... Thanks for your suggestions, everyone.