Two big waves struck so suddenly and violently that no one caught in the Foveaux Strait trawler tragedy had a chance to react.
Police yesterday gave fresh insights into the sinking of the 17m Kotuku that led to the deaths of six people, including three generations of Bluff's Topi whanau.
The last three bodies were recovered from the submerged vessel by the police dive squad yesterday.
"The boat was struck by two waves in a very short space of time," said Inspector Barry Taylor. "It happened so quickly there was not an opportunity to get to either [of the emergency] beacons that were on board ... or to the radio to make a mayday call."
Whether the radio was working was not known yesterday. That will form part of the investigation.
"To the best of our knowledge there were sufficient life jackets on board; however none were being used at the time," Mr Taylor said.
He would not comment on whether it might have made a difference if they had been worn. "It's too soon to say."
A series of inquiries into the tragedy have begun. Police will assist the Maritime Safety Authority, the Transport Accident Investigation Commission and the coroner in making their findings.
The possibility of the boat being overloaded may also be considered, but Mr Taylor said he had no information on that.
The Kotuku was travelling back to Bluff on Saturday with members of the Topi family who had been hunting mutton birds on Titi Island.
Yesterday, the six-man police dive squad faced sharks and the confined spaces of the sunken vessel as they recovered the bodies of Leslie "Peter" Christian Topi, 78, Sailor Roy Trow-Topi, 9, and Shain Jack Topi-Tairi, 9.
The bodies of Ian James Hayward, 52, Clinton Allan Woods, 34, and Tania Marie Topi, 41, were found on Sunday.
Kotuku skipper John Edminstin, 56, Paul Maurice Topi, 46, and Dylan James Topi, 16, survived by swimming to nearby Women's Island.
The Topi family should receive the bodies of their lost ones today.
"I think it would be fair to say that as tragic as it is, there's relief that all the bodies have been recovered," Mr Taylor said.
Jim Roderique, a lifelong friend of Peter Topi, said he would miss "the great bloke".
"He was a very straight-up fellow. If everybody was as good as Peter and his family, it would be a great country."
He said Mr Topi had been unable to go on other recent mutton bird hunting trips with his family because of illness, "but he tried not to show it".
"I would never think a person like Peter would end up that way because he was so careful," Mr Roderique said.
Police divers went down in pairs on three separate occasions yesterday to get the bodies trapped in the vessel, which was still intact and lying on its side on the sea floor.
Earlier, civilian divers had used an underwater camera to find the vessel and mark its location.
Dive squad head Senior Sergeant Bruce Adams said it was very rewarding for members to be able to return the bodies to the family.
The isolated location and the cold temperatures made the recovery a difficult one. "There were several sharks seen by the topside craft and we were briefed that they were seen on one of the dives," Mr Adams said.
Mr Taylor said the impact of the tragedy was far-reaching.
"The entire Bluff and Southland communities will in some way feel the effects of this tragedy."