"A large metallic grey dorsal fin signalled a big shark, a short-fin mako," Constantine wrote in the piece published March 11. "But wait, what was that orange patch on its head? A buoy? An injury?

Initially thought to be a shark bite, the injury may have been caused by a surfboard fin. Florida averages 19 unprovoked shark attacks annually. A 12-year-old was recovering Monday after being ...