RedactedNarrative: UNIT 1 WAS A RENTAL PWC FROM MYRTLE BEACH WATERSPORTS.  AN UNIDENTIFIED VESSEL WAS HEADED SOUTH NEAR GRANDE DUNES MARINA.  THE WAKE FROM THE UNIDENTIFIED VESSEL WAS HIT BY UNIT 1.  UNIT 1 OPERATOR WAS INEXPERIENCED, DID NOT MAINTAIN A SAFE DISTANCE FROM THE DAY MARKER, AND DID NOT TAKE THE PROPER ACTION AS THE WAKE APPROACHED.  UNIT 1 STRUCK THE DAY MARKER SNAPPING THE MARKER AT THE WATERLINE.  TWO OF THE THREE OCCUPANTS SUSTAINED INJURIES.