Barry Lennox ) writes:

A friend rolled a tin of (expensive) paint off his moored boat into
about 15 feet of water, about 20 mins of fishing with a big magnet
retrieved it, much to his relief.

That's the sort of thing you'd see in Edmund Scientific ads and
catalogs years ago. They were one of the obvious places to get really
strong magnets before we had a wealth of items to take apart and
salvage magnets from.

Michael