Vessel 1 was leaving Lighthouse Marina, Vessel 2 was heading to Lake Murray Marina.  Vessel 1 was traveling SE.  Vessel 2 was traveling NE.  Operator of vessel 1 states that he sees Vessel 2 on his radar and sees the lights at approx. 100 yards away.  Vessel 1 then strikes Vessel 2 on the port side in the middle of the boat.  Vessel 2 is crushed.  Two female passengers are killed and two male passengers seriously injured.  Three of four occupants of Vessel 1 are ejected overboard. 