I tipped my Enfield out of a canoe once but a piece of stove pipe as a reverse perascope and a pocket fisherman and it was found in 15 feet of water. It hat one up the throat though (safety on) so it has hooked on the sling just in case by my buddy's. I was tucked in a sleeping bag warming up. I learned to pit a lanyard of some sort on after that but fortunately never needed it. And I did have on a Mustang Floater Coat as well
First useful function of a Pocket Fisherman I've ever heard of.