Oh - and Dr. Bob's estimate for DIY repair is about right. I'm in Whitehorse, which brings costs up compared to southern centres - my total cost was ~2.5k CAD (incorporating some new tools, and expensive purchase/shipping of CarbonBond compared to less remote locations).
I addressed a wet transom core on my 2004 22 Cruiser this spring. In case it's useful in seeing potential steps for Dr. Bob's first repair option (core removal and replacement with cast material), my repair log is here: http://www.c-brats.com/viewtopic.php?t=32753
Happy to answer questions if...
We planned to pour slowly in stages, to allow each slug of compound to settle and spread, and to avoid trapping any air bubbles under a thick layer of compound. However, the consistency of the compound as we poured it provided me with good confidence that there would not be issues with trapped...
A lot of work (much of it late nights that would have otherwise been occupied by sleep), but immediately rewarding in that it enabled our planned mid-June SE AK family trip to run as planned.
Everything reassembled and cleaned up, it was time for a test run. I'd performed some concurrent repairs on the Honda BF90A3 main motor (replacing a corroded tilt tube, and installing new oil seals on the upper end of the gearcase) which needed assessment as well.
Everything worked as it...