OK Bob, but only because you asked.
Working Yacht Club. We put our docks in and pull them ourselves. While we were putting the docks in, we drop 2 pilings off the dock into the water. I got to go swimming for them. Last year when pulling the docks, we realised on of our anchor chains, was not in place, 100' of chain to a 2x2 concrete block. I went looking for that, no joy on the block and chain, the current was to strong to do a good search, and we did not have a good location. The next weekend when we went to pull two more chains from the shore to the docks, the chain kept coming and coming, they had broke off the blocks, so back again to look for them. No luck there either but I did find a large mushroom anchor, 4 feet long 2 feet round, and a very large black bra, I could not stop laughing!!!
In the summer, when it is warmer I am going back to look for the rest of the missing blocks. This time if year after 30 minutes you can not feel your fingers.