For years, divers looking for lobster in the Florida Keys knew that the best place to find them was under some sort of shelter, whether a rock or something more artificial like a car hood.
John Coffin, who owns a marine salvaging business in the Lower Keys, said he got into using "casitas," or little houses, to find lobster in the late 1970s.
"It was a huge secret. I would never dive with another person," Coffin said. Still, even before GPS, other divers started following him around.