Returning to Florida from the Caribbean on a recent cruise we were cruising WNW along the northern coast of Cuba. We observed some animals (birds or fish) that appeared to emerge from the Ocean and skim the surface for approximately 30 to 50 yards and then crash solidly back into the Ocean. Sometimes single animals sometimes flocks of as many as a dozen animals.

It is hard to estimate their size (we were 7 decks up from the sea) but they seemed to be the size of a laptop computer or smaller. Their gliding speed appeared to be approximately 30-50 Miles per Hour.

Can anyone tell me what these animals might be.