I was camping last week in the Smoky Mountains (in a federal campground), and came across a couple skinny dipping in the river. They asked me to join them, and when I said I was in my 50's they said they were too! They were with another couple (on land), they both seemed like fun couples (we talked for a bit). It was about 4 pm, so in broad daylight. But no, it's not on my list of things to do before I die.