A diver who drowned while scalloping off Great Barrier Island had faulty equipment and was carrying too much weight, a coroner has found.
Neville Jon Poole, 42, was seen struggling and puffing when he surfaced after a 25-minute dive at Allom Bay in Okupu on January 25, 2011.
Mr Poole did not take a rope which was thrown to him and vanished under the water before he could be rescued.
His body was found by local divers shortly afterwards, with his dive weights and a bag of 60 scallops still attached.
Coroner Morag McDowell has made a raft of recommendations on dive safety after hearing evidence that Mr Poole's dive equipment, which was kept at his holiday home on Great Barrier, had been faulty.
Mr Poole had been holidaying on the island with his fiancee, her 10-year-old daughter and the daughter's 10-year-old friend.
He had gone out on a diving trip with the 10-year-old friend and a friend of his own, who skippered the boat, but dived alone.
Constable Ben Filiata, who examined Mr Poole's dive gear, found the first and second stage regulators - which convert high-pressure air in the cylinder into lower-pressure air for inhalation - had copper build-up, cracks and holes.
He also found Mr Poole's buoyancy compensating device, which helps to manage buoyancy above and below the surface, was not properly cleaned.
The device slowly inflated while descending, and sometimes failed to inflate when needed, wasting air supply and providing no buoyancy.
Mr Filiata noted Mr Poole's gas cylinder had been filled to about 200 Bar before the dive, but only 10 Bar of air remained - less than than 50 Bar needed to surface safely.
Mr Poole's 13.2kg weight belt was slightly too heavy for him, and the combined weight of the belt and his bag of scallops, which was tied to his buoyancy device, would have made him negatively buoyant.
Mr Filiata concluded the faults in Mr Poole's gear may have contributed to his death.
He said Mr Poole's negative buoyancy meant he was reliant on physical exertion to get to the surface. He could have struggled to ascend which, combined with reduced air supply, may have caused him to panic.
Once on the surface, he did not release his weight belt or scallop bag, which indicated panic and a possible lack of experience.
Mr Poole was not found with a knife, which he could have used to release the catch bag, although he may have been carrying one but lost it during the dive.
Coroner McDowell found it was clear the equipment was faulty and may have contributed to Mr Poole's death.
She made a number of recommendations, including that divers should always dive with a buddy, ensure their equipment is well-maintained and serviced annually, and check all equipment before every dive.
Divers should always carry a knife and should never attach their catch bag to themselves. They should abandon the dive if they felt unwell or became stressed, and should plan to surface with 50 Bar of air remaining.
The coroner also recommended divers should take a refresher course after an extended break from the sport.