Skimmer Surfing/bathing

I was checking out the shore birds at our local island beach, Tybee Island,when I noticed the odd behavior of a skimmer in the surf. I wasn't sure of what it was doing—I'm still not—but it was raising it's wings and diving into the froth, letting it bring it back to shore, then doing it all over again. Never seen anything quite like it before, at least not with birds.

It was playing!

Sounds like the same thing that my robins do in the birdbath! Unless he was surfing!