'Driver error' cause of jet boat crash - coroner

Ronnie Munro didn't arrive at Grey Base Hospital until six hours after the crash. Photo / File

A jet boat crash led to a South Island man suffering a fatal cardiac arrest as he was being treated for his injuries, a coroner has found.

Ronnie Munro died on the morning of March 8 last year in Greymouth Hospital. The day before, the 63-year-old was tossed from a jet boat that hit a rock on the Waitoto River near Haast on the West Coast.

Mr Munro was with a group of people spread across four jet boats.

He was sitting in the back of one, driven by Michael Thomas, which struck a rock when Mr Thomas failed to accelerate at the right time, throwing everyone into the water.

They were all wearing life jackets but Mr Munro was found face down in the water, apparently unconscious.

Another boat took him to shore. Blood was oozing from his mouth and he said he had a sore back and could not breathe.

The party set off a location beacon, while two boats returned to the launch site for help and a helicopter ride to Grey Base Hospital was arranged.

Mr Munro didn't arrive there until six hours after the crash. He was found to have multiple injuries from the crash including fractured ribs and fractures of the sternum.

He was also obese and had heart trouble and other medical problems. When a chest drain was inserted in preparation for a transfer to Christchurch Hospital, his blood pressure dropped and his heart rate increased.

As he deteriorated he was given CPR, but this was stopped after 20 minutes and he was declared dead.

Coroner David Crerar today released his findings into Mr Munro's "sudden cardiac death".

The coroner said the jet boating party was well organised and appropriately led and it had undertaken appropriate safety precautions.

"It is not known what difference, if any, earlier communication with rescue services would have made to the survivability of Ronnie Munro."

The collision with a rock was caused by "driver error" and Coroner Crerar said the decision allowing Mr Thomas to drive a boat he wasn't overly familiar with was "the direct cause of the crash the injuries and the death".

The Queenstown Lakes District Council harbourmaster said Mr Thomas shouldn't have been driving the boat, especially on such a difficult stretch of water.

"An individual with better cardiac health and greater reserves may have been able to survive the injuries which were received by Ronnie Munro," Coroner Crerar said.

"There is no evidence, however, that there was any failure by those in the party who gave him first aid, those in the helicopter who cared and treated the injuries or those clinicians at Grey Base Hospital who attempted to stabilise Ronnie Munro for transfer to a tertiary hospital, provided care at anything less than best practice standard."

The coroner said delays in getting Mr Munro to hospital were understandable because of the remote location of the crash.