I seem go for a "swim" every year or two. This happen alot more often when I was younger for some reason. This time was fairly recent.

A couple of years ago I was fishing Nauset Inlet on Cape Cod. Trying to get a better drift,I inched my way out on to a sand bar until I could reach the drop off with my rod tip.
Of course, in this very fast water, the sand just melted away from under my feet.
Away I went.
Luckily, my stripping basket acted as a float and I was able to kick/tiptoe my way to shore without getting too wet. Otherwise it would have been a much longer and colder swim.
I spent the rest of the day casring from shore.