RedactedNarrative: Witness stated he was traveling southbound through Wahweap bay, just east of the marina, along the breakwater. Witness then noticed a houseboat (V1) traveling directly at him in his navigational lane.  Witness estimated that V1 was traveling at “two or three times” his''s speed and he stated he was traveling approximately 8MPH. Witness stated he turned slightly to starboard to avoid V1 and that V1 eventually moved out of the path of V2 by turning starboard as well. Witness said while V1 was passing V2 on the port side, it turned hard to port, behind V2 and barely missed the port side of the stern of V2. This caused V1 to run into the pontoon boat that V2 was towing behind them. Witness stated that V1 did try to reverse however due to the size and weight of a houseboat it was unable to stop in time to avoid hitting the pontoon boat.
  
  V1 struck its starboard bow on the pontoon''s port bow resulting in damage to the railing, gate, and seat area on the pontoon boat. The tow rope then broke and the pontoon boat was set adrift.