The last time I saw this one... It involved a blue T-shirt, pair of underwear, a diver, and tube of rubber mastic.
Boat ran aground, shaft strut poked up through the hull
... flooded, laid over on a sand bar and required some salvaging. Surprisingly, a T-shirt, pair of underwear and some rubber mastic... will withstand full reverse of a big diesel
as someone backs it off of another sand bar.
(Found out about the T-shirt, underwear, and tube of mastic after my dad bought it... and had her hauled out. Doh.)
In the future, I'd like to see some stout canvas used as Chief Engineer
suggests. It's just wrong to pull wadded up undies out of the bottom of a boat.