RedactedNarrative: OPERATOR 1 AND SWIMMER 2 WERE SWIMMING AND BOATING. SWIMMER 2 BEGAN TO STRUGGLE IN THE WATER AND OPERATOR 1 ENTERED THE WATER TO RENDER AID. A WITNESS WAS ABLE TO SAFELY REMOVE SWIMMER 2 FROM THE WATER, BUT WAS UNABLE TO ASSIST OPERATOR 1. OPERATOR 1 WENT UNDER THE SURFACE AND DID NOT RESURFACE. NO DAMAGE TO VESSEL.