NB: The below is a brief plain English summary of key points in the report. The Commission's report speaks for itself -- you can download the full document here:
Maritime NZ’s survey system does not adequately assure the integrity and safety of fuel systems because the rules do not require that the entire fuel system is inspected.
TAIC is recommending that Maritime NZ improve its system for boat surveys and alert marine surveyors and the broader sector to the importance inspecting a vessel’s complete fuel system.
The i-Catcher was an 8-metre aluminium pontoon boat built for private use in 2003, that entered commercial service in 2009.
On the morning of 10 September 2022, ten passengers had chartered the vessel for a photography trip.
At 10:05am the i-Catcher rapidly capsized after contact with what initial inquiries suggest was a whale. The skipper and five passengers climbed onto the upturned hull. Five other passengers surfaced in the air pocket inside the boat.
The skipper called 111 and the Maritime Operations Centre issued Mayday relays. Responding vessels recovered the five passengers and from the upturned hull. Later that day, the Police National Dive Squad retrieved the five passengers from within the vessel, deceased.
What went wrong
Flaws in the vessel’s fuel system almost certainly allowed fuel to leak into the air pocket of the upturned vessel and very likely reduced the survivability of the accident.
Evidence reviewed by the Commission’s medical consultant identified that all deceased passengers showed symptoms of petrol exposure, consistent with inhalation and absorption of petrol fumes. Petrol was on the water surface in the air pocket. High exposure to petrol fumes in a confined space reduces survivability; it affects the cardiac and central nervous systems and can rapidly lead to confusion, loss of consciousness and sudden death.
The fuel system included primary and secondary vent hoses for the fuel tank:
Primary fuel tank vent: there was no hose clamp to secure the primary vent hose to the fuel tank, only sealant. Some sealant had broken away, so fuel could leak from the insecure connection.
Secondary fuel tank vent: the secondary vent hose was ineffective because it did not vent to outside air; instead it vented into the sealed metal tubing frame fitted to the boat. Connecting the secondary hose to the frame was an alloy pipe, in which investigators found a hole, 12mm x 6mm. This was the main fuel leak source, a significant safety hazard, risking:
Fire or explosion if fuel leaked when filling the tank
Petrol fumes in the air pocket, should the vessel overturn.
Surveys did not identify the hazard
Maritime Rules required i-Catcher’s machinery [including its fuel system] to be “of a design and construction adequate for the service for which they are intended; and so installed and protected as to reduce to a minimum the danger to persons from moving parts, hot surfaces and other hazards during normal movement about the ship.”
In i-Catcher’s thirteen years of commercial service, it was surveyed by five different marine surveyors. The Commission is yet to identify when the hole appeared, but none of the survey reports show inspections of the fuel system below the deck plate, or any alert that the secondary vent tube did not actually vent to outside air.
Maritime New Zealand’s survey system does not adequately assure the integrity and safety of fuel systems because the rules do not require that the entire fuel system is inspected.
Inspections difficult: Vessels similar to i-Catcher represent a significant portion of New Zealand’s commercial fleet. Their fuel systems can be difficult to access – for example, gaining access may require disassembly or destructive measures (as TAIC found in inspecting i-Catcher).
Rules insufficient: undetected high-risk deficiencies are more likely because the Rules do not require surveyors to inspect the whole fuel system as a critical item.
To address these issues, the Commission’s recommendations to Maritime NZ relate to:
Ensuring the integrity and safety of fuel systems through the survey system. [Recommendation 021/23]
Surveyors’ professional practice around fuel system inspections. [Recommendation 022/23]
Sector-wide knowledge by all industry stakeholders regarding the importance of complete fuel system inspections. [Recommendation 023/23]
Further lines of inquiry
The Commission is continuing with a full inquiry into this accident. A final report, setting out findings, safety issues and further recommendations, if any, will be issued at the completion of this inquiry. Lines of inquiry include, but are not limited to:
cause of capsize;
life jacket education; and
emergency response to maritime accidents.
No repeat accidents – ever!
The principal purpose of the Transport Accident Investigation Commission is to determine the circumstances and causes of aviation, marine, and rail accidents and incidents with a view to avoiding similar occurrences in the future, rather than to ascribe blame to any person. TAIC opens an inquiry when it believes the reported circumstances of an accident or incident have - or are likely to have - significant implications for transport safety, or when the inquiry may allow the Commission to make findings or recommendations to improve transport safety.