why the BLACK SKIMMER can still fly so fast while dragging the water with its bill.

Black Skimmer is the only bird that has two unique characters: A) the lower bill is longer than upper bill and B) having cats eye. Skimmer skims the water for food. It's the most hard working bird, if not the only one.

"Sea Skimmer", after the name of Black Skimmer, is the missile that flows close to the surface of water.

Looks like it is changing its course to strike JFK airport: