RedactedNarrative: While in operation, the motor on Vessel 1 quit when a large wave came over the back of Vessel 1, swamping the vessel.  Passengers aboard Vessel 2 came to the aid of Vessel 1, bringing three of the four passengers aboard Vessel 1 at the time of the incident on board Vessel 2, and starting to tow Vessel 1 to the shore.  Before starting the tow, the Operator remaining on board Vessel 1 did don a PFD.  Vessel 1 continued to fill the water, eventually capsizing and putting the Operator of Vessel 1 into the water.  Passengers on board Vessel 2 recovered the Operator of Vessel 1 from the water and transported him to shore where he was treated for hypothermia.