RedactedNarrative: A  open motorboat was traveling north back to shore due to rough seas. The vessel became overwhelmed by water and sank, leaving all four occupants in the water for approximately an hour before being rescued. Hypothermia was the primary injury for all four occupants. All occupants were wearing a PFD and performance was successful. Two occupants died and the other two occupants were hospitalized and treated.  The vessel sunk and was not recovered. Little knowledge of the vessel is known. Vessel was a total loss. Enforcement action was taken against the Operator- Operation of unregistered vessel and operation of a vessel without a safe boating certificate. 2 injured, two dead