RedactedNarrative: VESSEL 1 WAS HEADED EAST PARTICIPATING IN A SANCTIONED EVENT ON LAKE EUFAULA.  THE AREA WAS HEAVILY CONGESTED AND THE WATER WAS VERY ROUGH DUE TO HIGH BOAT TRAFFIC.  VESSEL 1 CAUGHT A LARGE WAVE AND BEGAN TAKING ON WATER AND BEGAN TO SWAMP.  ALL OCCUPANTS OF VESSEL 1 DONNED LIFEJACKETS AND ATTEMPTED TO BAIL THE WATER FROM THE VESSEL.  VESSEL ONE BEGAN TO ROLL OVER AND ALL OCCUPANTS EXITED THE VESSEL BEFORE IT SUBMERGED TO APPROXIMATELY 90%.  OCCUPANTS WERE PULLED FROM THE WATER BY PASSING BOATS AND MARINE ENFORCEMENT UNITS.  AREA OF THE ACCIDENT WAS APPROXIMATELY .5 MILES EAST OF THE US69 NORTH CANADIAN BRIDGE AND APPROXIMATELY 1.4 MILES SOUTH OF INDIAN SPRINGS BOAT RAMP AND APPROXIMATELY 1.6 MILES NORTH OF THE CITY OF EUFAULA.