Regarding PB Blaster, it's good stuff but I haven't found it to be a panacea. I had several stuck bolts on my recent catamaran restoration project and literally kept them bathed in PB Blaster for 1 or 2 days, yet to no avail except for one of the bolts (which still came out really tough!). At any rate, I wouldn't do anything based on just getting PB Blaster to the site and count on that to fix it (though it certainly might help). It sounds to me like Southern Cross's idea would be best, although you might want to consider the possibility of putting an access portal on top of the hull toward the transom and coming at it from that angle. Bummer of a situation, that's for sure.

Oh, regard the camera, my dad always said that you can't have anything good with kids around... <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />