Newsletter- Jet boat impacted rock wall Skippers Canyon

5 Mar 2020
A composite image showing a jet boat's jet unit and its separated components. The left image (Image 1) displays the rear of a blue jet boat with the jet unit in focus, highlighted by a yellow box. The right image (Image 2) is a close-up of the disassembled jet unit, showing the steering nozzle and tailpipe. Red circles mark the locations of broken stud bolts that were meant to secure the two halves of the jet unit together. A label indicates the location of the fourth, unbroken stud, which is hidden
Image 1 - location of jet unit; Image 2 - the separated steering nozzle and tailpipe, and broken stud-bolts

FINAL REPORT: MO-2019-201 Jet boat Discovery 2, contact with canyon wall, February 2019 

NB: The below is a brief plain English summary of key points in the report. The Commission's report speaks for itself. 

What happened 

A commercial jet boat was steering at speed through bends in a narrow section of the Shotover River in Skippers Canyon. The steering failed, as did the reverse thrust and the boat continued under momentum. It was travelling at 20 to 30 km/h when it hit a rock face. One passenger was thrown partly overboard and received a broken leg. The other passengers received minor cuts and bruises. All were evacuated by helicopter.

A blue jet boat named Discovery 2 with Skippers Canyon Jet branding sits on a dual-axle trailer inside a shed. The boat has visible damage to its bow, with significant deformation and cracks in the metal structure. The trailer has a winch and rope securing the boat, and the shed has corrugated metal walls and wooden beams. The interior of the boat is visible, showing seating and a roll bar.

Why it happened

Jet boating at speed in narrow channels and rivers is a high-risk activity because there is very little margin for error, and safety depends on a highly skilled driver always being in control of the boat. On this occasion, the jet unit steering and propulsion system failed, making it impossible to control the boat.

  • The jet unit's steering failed because three of the four stud-bolts holding the steering nozzle onto the tailpipe assembly had broken
  • The stud bolts broke due to fatigue cracking.
  • The fatigue happened because nuts on the bolts were not tightened to the manufacturer’s recommended torque.
  • The nuts weren't tight enough because the operator's hazard focus was less on mechanical matters than on operating conditions and driver training.
  • The focus more on conditions and training happened in the context of a regulatory focus in that direction [to address the causes and circumstances of previous jet boating accidents].

 

What we can learn

Summarising the key lessons for all jet boating operators:

  • Have a regime to follow the manufacturer's maintenance instructions and guidance. (The operator in this case has addressed this need with an improved maintenance programme)
  • Jet boat safety depends as much on mechanical factors as it does on driver training and operating conditions. Operators need to identify and take extra care to maintain critical components that, if defective, would pose significant risk.
  • Operators need to identify and mitigate risks and hazards specific to their own operations. This process will help improve safety standards over and above the minimum required by the Maritime Rules.

 

Who may benefit

In the interests of improving safety in the adventure tourism sector, the Transport Accident Investigation Commission has made a recommendation to the Director of Maritime New Zealand to address the requirement for operators to identify safety-critical systems and ensure appropriate maintenance schedules are in place. Maritime New Zealand is working on new guidance and awareness-raising initiatives for the sector in 2020.