Many years ago USN took a few of us into the Girls of Mexico for some deep water survival training. Wearing all our flight gear...helmet boots vest flight suit etc., they booted us out of a boat and said 'see ya later'. The automatic inflators didn't work so we had to inflate them ourselves. No big deal. Mine, and I suspect a few others, had minor leaks. No big deal.
So, there I sit flopping around in the water for a few minutes, occasionally putting aa bit more air into my life vest. As it turned out I was the next to last guy to get picked up by the help. As I am sitting there I look off to my right and see two dorsal fins headed my way. Uh oh, they became a big deal in a hurry. Turned out to be a couple of curious dolphins.