The kōhanga reo teacher fell off under the bridge and forward-rolled into a concrete pillar.
Despite attempts to resuscitate her, she died at the scene from multiple injuries, including head injuries.
Her family said that at the time of her death, Wilson had just celebrated her 40th birthday after a tough year of cancer treatment.
She found out that she was free of cancer five months before she died.
After her death, Maritime New Zealand investigated and found that the jet ski was travelling about 11 knots (20km/h) just before Wilson fell off the sea biscuit.
Maritime rules limit vessels, including jet skis, to 5 knots (9.25km/h) within 200m of structures, including bridge pillars, or the shoreline.
The rule also applies within 50m of any other boat and within 50m of a person swimming.
Tira Wilson was known as a wonderful mum and caring friend.
‘Too fast for the conditions’
“I find that operation of the jet ski at a speed too fast for the conditions, namely the concrete pillars of Town Bridge, was a key causal factor in Ms Wilson Wirihana Takanini sustaining her fatal injuries,” Coroner Heidi Wrigley said in her findings.
Neither the police nor Maritime NZ chose to charge the driver of the jet ski after Wilson’s death.
Maritime NZ reviewed the safety of the Waitara River and concluded that more signage was needed, upstream and downstream of the bridge, indicating the 5-knot limit.
This review was sparked in part by Wilson’s death, but also following a complaint from a member of the public that jet skis were speeding and there was only one faded yellow 5-knot limit sign.
A maritime officer went to the scene and reported that he couldn’t even see the faded sign, and that while there was other signage at the boat ramp, jet skis didn’t necessarily launch from there.
“I am not satisfied that the signage at Waitara River is adequate to assist in preventing further deaths like [Wilson’s],” the coroner said.
Coroner Wrigley said the signage was either absent or ancient, and barely legible in places.
She wanted “conspicuous signs” placed on the bridge and others along navigable stretches of the river.
A spokesperson for the New Plymouth District Council said in response to the coroner’s report that the council had already scheduled sign upgrades at its boat ramps on the river.
“New signage displaying the speed limit is also planned for the bridge, and we are just talking with Maritime NZ for the best way to do that,” the spokesperson said.
Coroner Wrigley recommended that Maritime NZ use its networks to publicise the 5-knot rule around bridges and structures on all navigable rivers in New Zealand.
“I consider drawing to the public’s attention to the 5 knots rule and its lifesaving potential … will increase knowledge of, and associated compliance with, that rule and thereby prevent further deaths like hers,” she said.
Wilson’s sister in-law, Toni Materoa, said Tira was “terribly missed”.
“I hope it [the coroner’s report] brings awareness to other people who are using boats and skis,” she said.
Maritime NZ’s General Manager, General Regulatory Operations, Michael-Paul Abbott, said the government agency extended its heart-felt condolences to Wilson’s whānau and loved ones, and to others involved in the incident.
“We have made contact with New Plymouth District Council and will support them to review and replace boating safety signs on the navigable sections of the Waitara River, including for speed limits,” Abbott said.
Ric Stevens spent many years working for the former New Zealand Press Association news agency, including as a political reporter at Parliament, before holding senior positions at various daily newspapers. He joined NZME’s Open Justice team in 2022 and is based in Hawke’s Bay. His writing in the crime and justice sphere is informed by four years of frontline experience as a probation officer.