RedactedNarrative: The boat was anchored in a deep hole on flathead river. The occupants were jigging for whitefish.  There was very little current in that spot.  The boat was anchored from the front and back of boat, so the boat would not spin.  The boat was an older, 10 foot,  aluminum boat with short sides. The passenger was sitting in the front of the boat, and was wearing chest waders, and a type 3 self inflatable PFD.  
  The Operator, was in the back of the boat, wearing chest waders, and had a type 3 PFD on with the buckles not buckled.  For an unknown reason the operator leaned to the left suddenly, causing the small boat to tip and take in water.  The water rushed in causing the boat to submerge and tip over. Both occupants fell into the water. The passenger PFD inflated and he was able to swim to the east shore of the river .  The Passenger pulled the operator, who was unresponsive,  floating on his back, with his face up, to the shore.  The passenger began CPR.   Two Bear Air Rescue arrived and EMT continued CPR. They were not able to resuscitate the operator.
  