This is a Skimmer bird. They use their much longer lower beak / jaw
to skim the water surface for food. They move VERY quickly, do not wait
around for you to photograph them.
In fact, this one was being as elusive as he could, until I caught him
off guard for just a moment, having taken off in flight and having just
raised his "landing gear" back into it's tuck position underneath.
Sorry I overprocessed this one so much it no longer represents the shasp
crisp image the original is.
They are one of my favorite birds, next to the Emperor Penguin