Three men who died aboard a fishing vessel in 2015 could have been saved if a proper alarm had alerted them to rising water below deck.
Terry Donald Booth, 55, Paul Russell Bennett, 35, and Jared Reese Husband, 47, died when their fishing vessel Jubilee sank off the Canterbury coast in the early hours of 18 October.
The vessel drifted about 20km from the mouth of the Rakaia River in rough conditions, after the crew packed up for the night.
At 4.30am the skipper sent out a distress call saying the boat was taking on water and the crew were making their way to the life raft.
Debris from the vessel, an oil slick and an empty life-raft were found at the spot where the distress call was made.
The Transport Accident Investigation Commission (TAIC) found that it was likely a crew member had left a wash hose running through a hatch and into the fish hold below.
"This was the only space that could, alone, have caused the Jubilee to sink, even before the hold was completely full of water," it said.
If the fish hold had filled with water, the stability of the vessel would have been reduced and become more susceptible to rolling and potential capsizing by a large wave, it said.
The investigation found that the Jubilee was not fitted with an automatic alarm to alert the crew to rising water levels in that part of the boat.
An alarm may have prevented the disaster, the commission said.
"The absence of a bilge high-level alarm for the fish hold and the absence of an indicator in the wheelhouse alerting the crew when the bilge pump was running were missing checks in the system that would have alerted the crew and then about as likely as not prevented the sinking."
The was also no visual alarm in the wheelhouse to alert crew, it said.
The commission said that the wheelhouse did not have enough escape options for the crew.
The room was only fitted with a heavy sliding door at the rear, which would be "almost impossible" to manoeuvre if the boat had capsized, it said.
The fishing company, Ocean Fisheries, owned by the Stark Family, has now fitted the other boats in their fleet with alarms, more bilge pumps and better escape measures.
The chief executive of Stark Bros, which owns Ocean Fisheries, Andrew Stark, said he was unable to discuss the details of the report at this stage as other investigations were under way.
"The sinking of FV Jubilee ... and the past 18-plus months have been hard for ourselves and particularly the families of our three crewmen," Mr Stark said in a statement.
"We have welcomed efforts to establish the cause of the sinking, and have co-operated with and had input in the TAIC investigation.
"It is positive that the TAIC report has been finally completed and released, however it is but one report and one step in an ongoing investigation process by authorities."
The FV Jubilee was built by Stark Bros in their Lyttelton ship building facility and first launched in 2008 by Ocean Fisheries Ltd.