It almost certainly seems to be a mere manatee, but there's just no getting around that manatees do not possess trident tails. This obvious drawback has baffled skeptics who, against the evidence, still insist it just must, somehow, be a manatee.
Well, in this case, the skeptics may be right. The Florida Fish and Wildlife Conservation Commission discovered a manatee likely to have been injured by a boat propeller (and possibly more than once) at some point in the past, with its tail deformed into three separate parts. Because of the unusual shape of the manatee's tail, it leaves a very distinct triple wake on the water’s surface while cruising just below it.