On 9/18/12, at approximate 1145 hours, V1 was departing the area of Black Canyon, Boulder Basin, Lake Mead National Recreation Area.  The operator OPERATOR, began a long, gradual turn to port which brought the vessel back toward the mouth of Black Canyon.  He then attempted to turn the vessel to starboard, he felt the vessel "jump" to port and it began turning in a very tight spiral to port.  He had no control of the steering.  The vessel did two spirals before he could drop the throttle to zero.  OCCUPANT was sitting in the passenger seat next to the operator.  OCCUPANT1 was standing on a raised portion of the deck, directly behind the operator. The sharp turn caused OCCUPANT1 to be thrown overboard.  OCCUPANT was thrown into the windscreen, breaking it.  When V1 spiraled, the propeller impacted OCCUPANT1, causing considerable damage to his left side, nearly amputating his left arm.  With the steering inoperable, they couldn''t transport OCCUPANT1 to medical attention.  They rendered first aid as best they could, until medical assistance from the National Park Service arrived.  They transported OCCUPANT1 to a waiting medical transport helicopter, which took him to University Medical Center in Las Vegas, NV. OCCUPANT1 was checked into the Trauma Intesive Care Unit where he was diagnosed with the following injuries: Fractures in the left humerus, left ulna, left heel, left fibula.  Injury to hypatic artery. Extensive avulsion to left arm, left leg, and left heel.  Extensive soft tissue damage along entire left side. Grade IV laceration/contusion to liver. Left arm was nearly completely severed.  Extensive surgery was prescribed for the coming days. OCCUPANT refused treatment, but suffered abrasions to his right arm and elbow, along with a stubbed toe when he was thrown into the windscreen. OPERATOR received no injuries.  An examination of V1, post accident, showed that the external hydraulic steering cylinder had become unattached from its anchor, most likely when the operator attempted to turn back to starboard, which would prevent the vessel from receiving any steering input from the helm.  A certified marine technician examined the steering and believed the steering system was properly installed and that the failure was due to the age of the vessel and it simply broke during the turn.
Boulder City                  