Previously I have seen Black Skimmers skimming on calm ponds. On this day I saw a few from this crowd doing it in the ocean.
As you can see above the Atlantic Ocean surf was not particularly rough, but it sure is a different challenge for a Skimmer.
This one hugged the surf line, ignoring other birds along the way.
With the surf in constant motion he had to also alter his path. I did not see him catch anything, although they can gulp it down on the fly and keep on moving.