A report into a White Island Tours boat fire which forced 60 people to jump overboard says smoke detectors and an appropriate firefighting system could have helped.
The report is repeating calls for Maritime New Zealand to make fire alarms compulsory.
The Pee Jay 5 was on its way back from White Island in January 2017 when the fire took hold.
The 53 passengers and seven crew were forced to jump overboard, many of them without life jackets, as the vessel was consumed by the flames and sank.
Australian tourist Brendan Paterson was among those on board with his two sons.
"I spent the better part of the year just having nightmares and difficulty sleeping, lots of nightmares about thick smoke and that sort of thing," he said.
Two years on, a report by the Transport Accident Investigation Commission (TAIC) reveals there were no fire alarms on board and the firefighting system was the wrong type for that instance.
Maritime rules do not require the use of fire alarms on boats.
"Fire is a high risk in vessels and the likelihood of it is quite [high] in vessels of this size," said TAIC chief investigator Tim Burford.
"It's fundamental that the crew are alerted as soon as possible before a fire takes hold - that way they have more of a chance of putting it out before it becomes too big and or so they can start getting people off the vessel a lot sooner."
Mr Paterson was caught by surprise about the lack of regulation around fire alarms.
"I found it a bit surprising - I just thought it would've been mandatory," he said.
White Island Tours have since been acquired by Ngati Awa Group Holdings.
It didn't want to appear on camera today but said the report confirmed it met all Maritime NZ requirements and will continue to do so.
The Commission is renewing calls for Maritime NZ to change the rules.
"We have a piece of work under way at the moment to review the rules that relate to ship design construction and equipment carried and it will be covered in that review," Keith Manch, director of Maritime NZ told Newshub.
While the report brings some closure, the cause of the fire will never be known because the boat burned and sank leaving no evidence.