What is the coolest/most interesting bit of flotsam or jetsam that you've found?

I just nudged the BVM over to shore and propped her on one of the abandoned concrete barge docks (where the steel mills used to be) so she could bestow her blessings upon all the assorted boats and flotsam passing by.

On popular rivers like in California we call it eddy shopping. Unopened beers, sunglasses on floats, chap stick, paddles, hats, suntan lotion, dry bags.