RedactedNarrative: V1 was traveling downstream about 20-25 mph on the right side of the channel which runs down the middle of the river.  V2 was traveling upstream at about 20-25 mph when he saw a green bow light & a spotlight pointed straight at him at approximately 500 yds away and to his left. V1 immediately turned off the spotlight to not shine in the eyes of V2 yet states his running lights were still on. V2 states after the spotlight was shut off, there were no other lights including the green bow light & he proceeded with caution.  Shortly after, V2 claims that V1 appeared in front of him & he had to swerve left to avoid the collision. By swerving left, V1's front starboard side collided with the rear starboard side of V2, near the engine compartment.  The collision caused a huge hole in V2 which made it sink within minutes of the accident.  The vessel is still in the Missouri river.  None of the occupants were wearing a life jacket.