What was meant to be a fun family trip on the jet boats turned disaster on Sunday afternoon, when one boat hit a gravel bank and rolled.

The crash led to serious injuries among its occupants, some of were children of unknown ages. The group was winched out by helicopters, suffering broken limbs and spinal damage.

Three were rushed to Christchurch Hospital and are all now in stable condition, according to a hospital spokesperson.

Maritime NZ told the Herald on Sunday morning they’d received a distress beacon alert just after 2pm, the beacons are standard issue on jet boats and activated during an incident.

Rangitata River runs from Mt Hutt to the east of the South Island. Photo / Google Maps

This alert came from a section of the Rangitata River, running from Mt Hutt to the east of the South Island.

Rangitata River is a braided river which features numerous channels that jet boaters can choose to travel down - varying in width and depth.

In the case of Sunday’s distress alert, the incident had occurred in a rural section of Canterbury.

Maritime said it responded with its Rescue Coordination Centre, finding three people with injuries that included a head injury, spinal injury and a broken leg.

Two others were also at the scene of the crash, but weren’t injured.

The Herald can reveal the boat in question had contained a group of five that were taking part in a family outing. There were seven jet boats exploring the river at the time.

The Rangitata River is a braided river which features numerous channels that jet boaters can choose to travel down. Photo / Google Maps

No other boat was involved in the crash.

Jet Boat New Zealand’s Len French confirmed the incident had been caused by the jet boat hitting a gravel bank and rolling, causing considerable injuries.

Four helicopters were scrambled to provide help - two from Rescue Coordination and a private helicopter from Christchurch.

Additional helicopters from Christchurch and Greymouth also headed to the scene.

The Herald captured multiple rescue choppers arriving at Christchurch Hospital shortly before 5pm as they dropped off the injured patients.

According to French, the braided nature of the Rangitata River means there’s an “element of risk” that presents itself when exploring the channels.

The Herald captured multiple rescue choppers arriving at Christchurch Hospital shortly before 5pm. Photo / George Heard

“The [boaties] will choose which one they want to go down, there’s risk to it which I suppose is part of the fun of the sport,” he said.

Despite the risk, French hadn’t encountered a situation before where a boat had rolled on a gravel bank

“The water can be varying degrees of shallow in certain parts of the river,” said French.

“It’s seldom to hit a gravel bank, those rivers you’ll normally be going through shallow waters.”

The authority that oversees activities on public rivers is Environment Canterbury. Its harbourmaster, Guy Harris, said in a statement he was aware of the incident.

Helicopter drops off patients. Photo / George Heard

Harris confirmed Environment Canterbury was in talks with Maritime NZ about the situation.

“We have offered assistance if required.”

The harbourmaster’s office is responsible for navigation safety on all of Canterbury’s waterways - including streams and rivers.

In the past, Harris has run annual Safer Boating campaigns and promoted safe practices through a range of methods - from talking with boaties on the water to audits of cruise ships entering the ports.

“Maritime and the police are the agencies who lead responses to on-water accidents,” said Harris.

“We work closely with both organisations and provide support when required.”

The Canterbury region has a history of jet boat accidents, including one in October 2021 that injured eight in a crash.

A police spokesperson said at the time that three people had been flown to hospital with serious injuries, and three other people sustained minor injuries.

In 2005, an accident in the Waimakariri River led to a 53-year-old’s death, thrown off his boat into shallow water.

The man had been dropping off two friends for a fishing trip. One of the passengers saw the accident and notified police.