Operator of V1 was standing behind and to the starboard side of the console of his flats skiff fighting a fish.  He was putting the throttle in and out of idle as he was maneuvering around to get a better angle on the fish which had gone under a rock ledge.  As he was doing this, the fish came free.  He lost his balance, inadvertently shoved the throttle forward and fell overboard.  V1 then began making an unknown amount of circles around him.   He was then struck by the propeller causing his injuries.  He was able to swim and cling onto nearby mangroves.  V1 came to rest against a mangrove shoreline.  The operator was not wearing the engine kill switch lanyard or a PFD.; operator received propeller contusions, lacerations and a broken femur to his right leg from being run over by his own vessel.
KEY LARGO                     