Revellers on a party boat which a Mangere man fell from were not given a safety briefing or told the area he fell from was off-limits, according to passengers.
Some of those on the boat - including the man who organised the birthday bash - have raised questions over the safety of the trip, after police today suspended the search for the missing man.
But charter company Red Boats has denied the accusations.
Tevita Kava, 29, hasn't been seen since he fell into the Waitemata Harbour while celebrating his friend's 30th birthday on a Red Boats charter vessel with 50 others on Saturday evening.
Carl Tuvae, who had organised the party for his birthday, said there was no safety briefing at the beginning of the trip, and a friend had to tell him where the lifejackets were.
The group was not told the back of the vessel was off-limits, he said, and party goers were in and out of that area all night.
Previously, witnesses had described how Kava had gone to the back of the boat to check on men cooking on a barbecue. He leaned against a barrier, which released and he fell backwards into the freezing, pitch-black water between Kauri Pt and Birkenhead.
Red Boats owner Andrew Somers has said Kava was in an area at the rear of the vessel which was off-limits to patrons.
Today, Tuvae told the Herald the boat was going at quite a high speed while they cooked the barbecue.
"The boat was going fast, that's how we lost sight of him real quick.
"It'd be a different circumstance if they knew what they were doing."
Another partygoer, who wished to remain anonymous, made similar claims. He said he had been on a similar charter boat on a previous occasion and the boat had slowed down while they cooked and the barbecue was manned by a crew member.
He also said the crew's response was slow after Kava fell overboard, and the vessel was 100m past Kava before it turned around.
"I swear we were going as fast as 10 knots," he said.
"This situation could have been avoided if proper systems and processes were in place from the beginning of the trip and during the trip . . . If you get complacent these disasters can happen."
Somers denied the allegations, saying they were "not correct".
"We believe our staff followed all on-board procedures on the night and the incident is currently under investigation by Maritime NZ and the police, with our full co-operation," he said in an email to the Herald.
"We cannot comment further until the investigation has been completed, and we have a full understanding about the events on the night."
Kava's family gathered at Island Bay today for the third day since he went missing.
His little sister, Ellie Sitaleki-Lovo, said they continued to scour the coast line for any sign of him. Their dad could not speak yesterday and stared out at the horizon wishing for his only son to come home.
"Emotions have just been running around up and down. I really want his body to be found to give us closure. Instead of just having the waiting game and wondering what's happening.
"Dad is still the same, he hasn't said much. He's just quite numb and blank, trying to keep it together."
Paul Tuvae, who was on the boat, told the Herald yesterday that Kava went into the water while he was talking to men cooking on a barbecue at the back of the boat.
The barrier that gave way acts as a ramp to get on and off the boat when unlocked.
"It was a bit rough and the boat was moving pretty fast. The fact that he can't swim, he wouldn't have been able to float long enough."
Friends who saw him fall weren't confident swimmers either, and it took time for the skipper to be alerted and turn the boat around, Paul Tuvae said.
Somers said the ramp wasn't broken and staff had since tested it.
"The ramp is locked and tied in place. I'm unsure as to how it was unlocked and untied."
He said only one person was meant to be in that area at the rear of the vessel, for the barbecue.
Red Boats had cancelled all charters for the company's fleet until it was established what happened.
Somers said the company had owned the boat for 20 years and never had an issue with the ramp.
"We are devastated . . . we're working with the authorities to establish what has happened. The ramp's bolt is still in working order. I'm unsure why it was let down like that."