it was a manatee.

We were docked in Bahia-Honda state park... we were sittin around, and we heard this loud yell in the direction of one of the cigarette boats that was docked. Alot of people were heading over to the boat after a while, so we checked it out.

The guy with the hose owned the boat, apparently he was hosing the salt off his watercamaro, turned aft and saw the sea-cow propped up on the swim deck staring up at him, licking the fresh water rolling off the stern. He drank fresh water out of the hose for about an hour straight. The park ranger came out and said that its unusual for them to venture that far south from the everglades, and the big guy was probably in desperate need of some fresh water. The whole time a ranger was there, and the manatee seemed to enjoy the crowd... after he had his fill, he went back underwater and left.