An intoxicated jet boat driver found to have been speeding in the fading evening light before fatally crashing in a South Island river was three times over the limit.
The crash on Hollyford River in Fiordland National Park on March 18, 2019, killed well-known local farmer Shane Paul Gibbons.
Two other passengers on the jet boat were severely injured.
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The driver had a blood alcohol concentration about three times New Zealand's legal limit for driving a car, the Transport Accident Investigation Commission said in a new report.
He had been travelling at 35-50km/h with three others onboard in the darkening light when the boat hit a rock in a shallow channel.
The driver lost control and the boat skidded along gravel, coming to rest on a gravel bar in the middle of the river.
"The commission found it was virtually certain that the accident happened because alcohol consumption impaired the driver's ability to make good decisions and to operate the jet boat safely," chief investigator of accidents Aaron Holman said.
"The jet boat's speed meant the driver had less time to make good driving decisions, and in the flat lighting conditions, rocks and other risk features were hard to see, further affecting the driver's ability to set a safe course."
The crash was the third jet boat accident in two months early last year.
Nine were injured in a February 23 crash in Queenstown and Christchurch jet boat competitor Cameron Moore died during the Otago rivers jet boat race, near Luggate, two days later.
Gibbons and his partner Bridget Speight won the 2016 Southland Ballance Farm Environment Award.
The couple farmed sheep, beef and dairy support at Whare Creek on the southern end of the Te Anau Basin.
TAIC's Holman said the jet boat driver, who is not named, also failed to plan the trip on March 18 properly.
"In unfavourable environmental conditions, skippers need to plan their trip thoroughly, drive to the conditions, and recognise the limits of their ability."
In its report, TAIC called on Maritime NZ to improve its database on fatal accidents to better show those that had involved alcohol impairment.
It is also renewed its call for new laws preventing people in "safety-critical roles" being impaired by alcohol or drugs.