An officer from the police national dive squad has given a damning list of procedural failures that he believes contributed to the deaths of two divers at Lake Pupuke.
Senior constable Geoffrey Bray said there were several circumstances which lead to the deaths of Daniel Stoneham and Tyron North, in Takapuna's Lake Pupuke on July 15 last year, including that the two men were weighted too heavily for the fresh water dive - North's dive weights exceeded 12kg and Stoneham's 16kg.
The men were also using steel air tanks, which are heavier than the standard aluminium ones which the other divers were using.
The students, though having completed 15 weeks advanced diving course with Helix Training, were inexperienced for the 39m dive, Bray said.
"It's a depth to be respected. You need to have everything around you going right."
While the men were experienced diving in a range of conditions at 18m, they were unprepared for the range of factors that were against them at Lake Pupuke, he said.
"It was a dark place, it was a cold place."
Lake Pupuke is prone to "black water" due to its soft lake bed where silt can rise for several metres.
Torches, cutting equipment and dive computers or watches should have also been issued to each diver, Bray said.
Clear markers should also have been placed on the drop line so divers knew how deep they were and when to stop and check they had enough air.
Dive student Charlie Taylor talked about dramatic light changes at 30m on the dive.
"It went black just like someone switching the light off, as quick as that."
He was trying to signal to North, his dive buddy, to keep pace with their instructor, and saw him moving his hands along the line, and descending faster than anyone else.
Taylor heard instructor Nick Tuanna click his fingers to get North's attention, and believes he heard him but soon after North disappeared from sight.
Taylor said earlier some of the men including North and Stoneham had talked about calling themselves the "42 Below Club", referencing 42 Below vodka, as the 39m dive would be their deepest.
- Auckland Now