A law change may be needed to halt the mounting death toll of recreational divers, says Coroner David Crerar.
However, he stopped short of calling for regulations or a statutory licensing regime in a reserved decision released yesterday.
The decision followed a November inquest into the deaths of three divers off the North Canterbury coast at Motunau.
The Coroner said coroners' findings throughout New Zealand showed "alarming" similarities between deaths of recreational divers.
Eighteen divers died between 2000 and 2005 nationally.
Ten had a medical condition which could have contributed to their deaths and which should have disqualified them from diving, the coroner said.
Other causes were a lack of experience or recent experience, inadequate training, diving without a buddy and poorly maintained or poorly selected dive equipment.
The Coroner said the dive industry and recreational organisations were aware of the hazards and were promoting training and publicising the need for divers to be medically fit.
But he warned any further deaths particularly those with these common factors might prompt coroners to call for law reforms.
He found Neville Gordon Bennett, 35, a driller and helicopter pilot from Rolleston, whose body was never found, drowned on December 26, 2003, near Kirstens Reef, just south of Motunau Island.
He said Bennett may have suffered pain or panic while descending, lost his regulator, inhaled water and drowned.
The Coroner also found Steven Leslie Cope, 44, a Christchurch physiotherapist, who was never found, drowned on December 17, 2005, at North Reef north of Motunau Island.
Cope failed to meet his buddy after his descent and for "reasons unknown" had failed to surface.
The body of Stephen John Sintes, 41, a Kaianga mechanic, was found the day after he went missing while collecting crayfish just south of Motunau Island on March 19, 2006.
The Coroner found Sintes drowned after either panicking when he realised he was out of air or, being low on air, had tried to surface.
He said manner in which Sintes' catch bag was attached to him significantly contributed to his death as it could not be released quickly.
His catch of 25 crays was well over the limit.
The Coroner said there was an "industry best practice" for divers promoted by the New Zealand Underwater Association (NZUA) but compliance was voluntary and recreational divers were not required by legislation to have any formal qualification or training.
This left the onus on divers to ensure they were physically and medically fit for diving, that they were using appropriate equipment and were appropriately trained, particularly in buddy diving.
The Coroner called for the NZUA and Water Safety New Zealand (WSNZ) to "co-operate" with retailers of diving equipment and services and urge them to take a stronger role in supervising divers and for more effort to be made to ensure all divers became NZUA members so they could benefit from its training and education.
He has also called for Dive Boatmaster courses for those in charge of boats on the surface during dives and has recommended more emphasis be given by training agencies to the concept of "buddy" diving.
- The Press