RedactedNarrative: Unit 1 went to leave the dock at the Sand Bar and Grill resort on Lake Marie. All the dock spaces were occupied with moored boats.
  The operator of Unit 1 started to back out from the pier he was tied to. The boat went at a fast speed and unit 1  backed into Unit 2 causing damage to the po toons and front deck area. Unit 2 was pushed back with force to cause unit 2's outboard motor cover to sustain damage from the prop and lower motor of unit 4. Unit 4 had his motor tilted out of the water. Unit 2's owner stated that the operator of Unit 1 told him that his throttle was stuck. Unit 1 also hit the dock and caused a section of the dock to collapse.
  
  Unit 1 proceeded to get unit 1 under control. Unit 1 still appeared to owner of unit 2 and passengers on unit 2 to be giving the engine too much gas while maneuvering. Unit 1 then bumped against unit 3 which was tied on the pier next to where unit 2 was tied.
  
  The operator of unit 1 turned off his boat to keep it from moving. Unit 1 was tied back at the pier.
  
  The owner of unit 4 stated he did not want to be part of the report and that his boat had no damage to it. Prior to my arrival unit 4 was moved to the pier to the north of the pier where the crash occurred. Unit 2 had visible damage to the pontoons and front deck and the cover to the engine was damaged. Unit 3 had no visible damage to the starboard side, and owner was told after she looked closer to let us know if scratches or scrapes to unit 3 was visible. Unit 1 had damage to the prop and 'rear swim deck of the boat, which matched the design of unit 2's pontoons.
  
  The owner of Unit 1 started up his boat for me while it was tied to the dock. It was stuck in forward gear and would not go into reverse. However, the throttle would change engine rpms. So, if a person thought one had put it out of gear or in reverse gear the engine was still propelling forward not changing directions. I also tried the shifter lever and had the same results. I also noted that the boat was starting while in forward gear and recreational boat engines should not start unless in neutral. Unit 1 owner did . state that earlier in the boating season 'there was a problem and a mechanic found a cotter key missing from the control linkage. Unit 1 owner was advised not to drive the boat and to have a certified mechanic check his gear and throttle control.  Unit 1 owner arranged for his boat trailer to be  brought to the Resort and it was being pulled out of the water .
  
  Passenger on unit 2 complained of lower back and hip pain for when she fell in the boat at impact from unit 1. Owner of unit 2 was walking on the dock when this occurred. Witness was standing on the portion of the pier that collapsed with unit 1 hit it. He fell and hit his head.
  
  Antioch Rescue was in route before my arrival  and once they arrived paramedics treated both for their injuries. I was informed-by paramedics that both signed off from being transported to the hospital for further medical attention.