It was the "one second that changed everybody's life" on board the Zefiro charter yacht as it churned through the ocean off Rangitoto Island.
Tamarua fell at about 5.15pm - just 30 minutes before the end of a long afternoon staff party for Auckland catering company LittleWolf on April 1.
The outing was planned for the evening before Good Friday - one of the only nights of the year hospitality workers can relax, knowing kitchen service will not be beckoning the next morning.
When the 25-year-old was pulled aboard Zefiro several minutes later, onlookers say she was already dead.
"Everything stopped on that day. It's not just tough, it was horrifying, horrifying, horrifying," a witness on board the boat that day told the Herald.
On board the 18-metre yacht that day were 30 of Tamarua's colleagues and four Zefiro charter boat staff.
Maritime NZ says it is continuing the investigation into the accident that claimed the South Auckland mother-of-two's life.
"We are currently interviewing witnesses. Given the large number of witnesses and others involved, the interviews will take some time," a Maritime NZ spokesperson said.
"Investigations also include scene inspection, reviewing documents and other work that might be required."
It is not clear if the catering company is back operating fully.
The trauma for those involved that day is still raw and the findings of the Maritime NZ investigation are several months off.
"I can tell you all the suffering that came with it. It was an accident that happened on board, but it affected a lot of people," the witness said.
"People lost their work and the lady lost her life and her children lost their mother and it all happened in one second and nothing could have been done about it. It was a complete accident. Been out all day and half an hour to go, one second just changed everybody's lives basically."
The witness on the boat that day said they still don't know how Tamarua fell, but she was alongside a colleague who alerted the boat staff and then jumped in after her.
"I'm pretty shocked and devastated. I don't know what to say. I'm traumatised," the witness said.
"It was 100 per cent an accident. They're trying to work out how she fell basically. It was just instant surprise. No one saw anything and the only person who saw anything was the person who was with her.
"So basically she fell and he raised the alarm and the captain stopped straight away and turned around to go and pick up the person overboard and then that person who raised the alarm he jumped straight after her basically."
A member of the Tamarua family told the Herald they were informed the Zefiro charter yacht circled for several minutes trying to find Tamarua after she fell overboard.
That family member also said Tamarua was not "stupid" when drinking and did not believe she would have been recklessly hanging off the edge of the boat.
The series of events from this point onwards is still unclear, but it appears the colleague beside Tamarua who jumped in after her could not retrieve her.
A Fullers ferry heading back to Auckland came to assist the emergency, and witnesses say two men with lifesaving rings from the ferry eventually retrieved Tamarua's body from the harbour back onto the Zefiro yacht.
The Tamarua family member said it had been particularly hard for them after Danielle's father died in 2019. They buried Danielle on April 13 and held family memorials at her parent's home in Papatoetoe.
The Zefiro charter yacht has not been back out on Auckland's Waitematā Harbour operating since the accident.
Advertisements for renting the charter yacht, reveal at a minimum the LittleWolf staff party would have lasted four hours out on the Auckland water.
LittleWolf general manager Marcel Leydesdorff said earlier, his staff were "deeply distressed" after Tamarua's death.
"Danielle Tamarua was a beautiful, kind and much-loved member of our team. We are sad beyond words and extend our deepest condolences to Danielle's family and friends."
Leydesdorff did not want to comment further this week.
• A GiveaLittle page for Tamarua's partner and two young children has now generated more than $32,000.