Dive operator sentenced after propeller fatality

Lookout! Issue 34, December 2015

A man died after being struck by the propeller of a commercial vessel when he dived down believing he needed to free its anchor, during an excursion at a popular dive spot last year.
Unguarded propellers
Maritime New Zealand ©2021
The catamaran with its unguarded propellers.

The victim was the last client in the water and was planning to re-board after the final dive of the day.

After being told by the skipper that the anchor was snagged, he remained on the duck board, ready to dive and free the anchor if required.

The crewman then told the skipper that the anchor winch had freed the anchor. Despite further communication between those involved, the skipper was not aware when he started the engine that the diver had gone back into the water.

One of the unguarded propellers, checked while the vessel is in drydock.
Maritime New Zealand ©2021

Twin unguarded propellers protrude under the rear sections of this 14-metre catamaran, approximately 1.5 metres from where divers enter and exit the water. When the skipper put the engine into gear and moved the vessel forward, one of the propellers struck the diver and entrapped him.

He was unconscious when crew and fellow divers cut him free, and lifted him back on-board. They administered CPR, but the victim was pronounced dead soon after by a paramedic from the rescue helicopter.

As a result of its investigation, Maritime NZ prosecuted the company and the skipper under sections 15 and 19 of the Health and Safety in Employment Act 1992 for failing to take all practicable steps to ensure that no action or inaction at work caused harm to any person. Both parties pleaded guilty to the charges and were fined $50,000 and $25,000 respectively, and ordered to pay $50,000 and $30,000 in reparations.


  • Due to poor operational procedures and standards of communication, the skipper of the vessel assumed the diver was not in the water. He failed to check and engaged the vessel’s engines with fatal consequences.
  • Operators of all vessels must ensure that swimmers and divers are well clear of propellers before engaging them, and proceed with extreme caution in situations where swimmers and divers may be close to vessels.
  • There was an evident risk of miscommunication occurring in the context of a diver being told first to prepare to enter the water, and then, not to enter the water. A clear system of closed loop communications should be the practice used. This involves the receiver being asked to repeat back instructions so the sender knows the receiver has heard and understood the instructions.
  • There should always be a procedure that only trained people, such as crew, are permitted to dive under a vessel to free the anchor.
  • The twin propellers were not guarded. The installation of propeller guards – even partial guarding – is a practical step that can be taken to prevent the risk of harm to divers and swimmers.
  • There was no mention of the hazard of propellers in the vessel’s hazard register. It is a requirement under the Health and Safety in Employment Act 1992 (HSE Act), and referred to in the vessel’s safety manual, that hazards must be identified.
  • All hazards should be recorded in the hazard register, and safety warnings about propellers should be included:
    • in briefings for all dives
    • in a diagram on-board the vessel to show the danger areas for swimmers and divers.
  • Crews should be audited to ensure safety procedures are followed.
  • Maritime NZ is concerned about the number and seriousness of incidents caused by propeller strike in recent years. The lessons from this and similar accidents should be incorporated into operational procedures for vessels involved in diving and swimming operations.
  • Propeller strike can cause severe and often fatal injuries. In the interests of public safety, persons responsible can expect a strong response from enforcement authorities, to send a clear message of the consequences where operators are found to be at fault.

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