King County, Washington, home of Seattle, is passing an ordinance requiring all swimmers to wear a life preserver. Generally speaking, I would imagine if you’re actually swimming in the water, you probably know how to swim. If you don’t know how to swim, and you’re swimming in the water, you’re probably actually drowning. Presumably King County wants to stave off the possibility of someone who does not know how to swim trying to do it, and drowning.
Personally, I think all this interference with natural selection is going to come back and bite us in the ass in a few generations.