RedactedNarrative: V1 was traveling down river on the Blackwater River.  V1 struck an underwater log with the front left chine.  V1 rolled to the right and the bow ramped upwards.  The operator lost his grip on the tiller handle as the tiller handle swung to the port side of V1.  The operator lost his balance and rolled out of the starboard side of V1.  V1 made two circles around the operator before clearing him and stalling out against the bank down river.  The operator swam to the bank and became chilled due to the cold air and water temperatures.
  
  Subject was treated for hypothermia at the hospital.  He was released the same day with no further injury.