Safety Lessons from Marine Incident Investigation (AMSA Report) No.24 - December 2023

Passenger vessel collision with unseen submerged rock


A passenger vessel collided with an unseen rock, resulting in the injury of a passenger. The master navigated the vessel into unfamiliar waters that was not a normal or planned part of the passenger tour experience, and not authorised by the tour company.  

Owners and operators should ensure masters continue to conform to the planned or authorised route for the services they offer.  

What happened 

At about 4 pm on 4 October 2023, an eleven metre rigid inflatable passenger vessel operating a tour to a beach collided with an unseen rock. At the time of the collision, the vessel was travelling at 23 knots. The collision broke the tilt arm of one of the engines, which lifted from the water and hit a passenger in the back of the head.  

First aid was provided to the passenger on scene, and another vessel was sent by the operator to transport the passengers back to their home port. The impacted vessel made its own way back. 

The tour operator reported the incident to AMSA, investigated the incident, and implemented corrective action. They found that the vessel left the beach destination earlier than scheduled, and the master filled in time by providing an unscheduled tour/joyride into a bay that was not part of the normal tour route. The master was not familiar with these waters and was not aware of the location of any hazards such as unseen rocks.  

The tour operator reminded the master about the importance of following procedures and provided further education to their staff on the lessons learned, to ensure this incident would not happen again. 

Investigation findings 

The investigation identified the following factors: 

  • The master entered waters that they were not familiar with, and in doing so departed from the normal operations of the tour. 
  • The master was not aware of the hazard of submerged rocks in that stretch of water and collided at speed with the unseen rock. This caused a minor head injury to a passenger. 
  • There was no passage planning applied to the route taken by the master at the time of the incident. 

Safety message 

As part of the general safety duty, masters must comply with the safety management system for their vessel and its operations. This includes following the procedures and not deviating from the normal route unless immediate safety requires it.  

Masters must ensure that the intended route from point of departure to the intended destination is planned and cross-checked. 

If an incident does occur during a passenger operation, it should be reported to AMSA as soon as possible after becoming aware of an incident. 

Safety information on this topic 

General safety duties for domestic commercial vessels

How to report an incident

Safety Management Systems 

Last updated: 20 December 2023