Three possible reasons why the Rebecca May took on water and sank off the Coromandel coast this week are being investigated, says owner Dugal MacFarlane.
But Mr MacFarlane told the Bay of Plenty Times that, while it was still not clear why the steel-hulled 18m longliner sank on Tuesday afternoon, the two Tauranga crew on board were adamant it did not hit a Rena container.
"They say they would have known if they had.
"Although the possibility it hit a piece of timber or some other debris cannot be eliminated," he said.
Mr MacFarlane is principal director of the Whitianga-based Tuna Fishing Company that owns three commercial fishing boats, one of which was the Rebecca May that supplied fish to the Western Bay market. His 34-year-old son Wayne was captain of the boat, estimated to be worth $500,000 to $600,000, when it sank and he and his two crew had to abandon ship.
Mr MacFarlane snr said other possible scenarios being explored were an internal malfunction or whether the keel cooling piping system running the length of the vessel underneath had possibly broken off after hitting something.
The 8mm thick steel hull of the Australian-built boat would have been hard to penetrate, he said.
Mr MacFarlane said his son was sleeping while his two crew were taking turns on watch and says he only discovered the boat was taking on water after rising about 7.30am and realising it was sitting very low in the water.
He said it was not clear where the water was coming in from and, after waking the other sleeping crewman, the three men began trying to pump the water out over several hours using four pumps.
However, the water was coming in faster than they could pump it out, said Mr MacFarlane.
"Due to the amount of water sloshing around in the engine room, the 24-volt pumps short-circuited and burnt out and they could not keep up.
"Once the boat started to go down, it went very fast," he said.
The three men abandoned ship into the liferaft, and the emergency beacon was set off and picked up in Wellington by the Rescue Coordination Centre.
The centre issued broadcasts to other vessels in the area and the three men were picked up by the Lady Columbo.
Mr MacFarlane said how much water the boat had taken on was a key issue for both the Maritime New Zealand investigators and his insurers.
But it was a difficult investigation, he said, because the Rebecca May was now buried in about 365m of water.
It would be too expensive to try and recover the boat, he said.
Mr MacFarlane said it was not only the boat but there was about $150,000 of gear and $100,000 of electronic equipment on board.
He and his son were "gutted" because they had just started their busiest fishing period. Unfortunately, the question of future work for at least one of the two Tauranga crew members was now up in the air, as there was limited space on the firm's other two boats.