On 8 March Mr Weeds and good friend Graham Heaphy left Maitai Bay on the Karikari Peninsula by boat, dropped off two friends on the way and arranged to pick them up an hour later.
Conditions were calm and visibility under the water was about 10 metres, said the findings.
The divers got ready and checked their own dive equipment but did not check each other's equipment, which is a usual extra safety precaution, it said.
Mr Heaphy entered the water and swam down to check the anchor was secure then returned to a pre-arranged place to meet Mr Weeds however, he was not there.
When Mr Heaphy located him Mr Weeds did not have his regulator in his mouth and was breathing through his snorkel.
As the dive progressed, Mr Heaphy noticed his friend was no longer on the surface and he could not find him.
He went back to pick up the other two divers as arranged and the group continued to search for Mr Weeds and alerted emergency services.
Mr Heaphy dived down and found Mr Weeds lying on his back without his regulator in his mouth. His cylinder valve was open. They got him into the boat and returned to Maitai Bay, where they were met by police.
Mr Weeds was taken to Auckland Hospital, where a post mortem examination found the cause of death was drowning due to the effects of pressure change.
An examination of Mr Weeds' diving equipment found it was in poor condition but it was in working order and was not thought to be a contributing factor to his death.
"The inference being that Mr Weeds did not attempt to equalize on his descent which would have caused him discomfort and possibly made him unconscious," said the coroner's findings.
It was not known when Mr Weeds got into difficulty, but he may have inhaled water while the snorkel was in his mouth and on the surface, or from when he entered the water.
"The police believe that Mr Weeds was unconscious as he left the surface or shortly after and has drowned at this early stage. This being evident as he did not attempt to equalize as required resulting in a trauma to his middle ear given his dive cylinder was full or close to being full."
Coroner Shortland supported the recommendations for safe diving practice made by the Police National Dive Squad Report, some of which may have been overlooked by Mr Weeds and Mr Heaphy during their dive on March 8, he said.
These were: divers should have a dive plan, remain together during the dive, be familiar with the dive computer, including reading and understanding the manuals relating to that computer, recognise safe ascent rates and these should be followed at all times, and check and maintain their equipment.
In addition, they should not be afraid to abort the dive if they are feeling unwell, and if the dive buddy thinks their partner is unwell they too should not be afraid to abort the dive.
Mr Weeds died about a month after his wife passed away from illness.
