After six children risked their lives by trying to float down the Manuherikia River on inner tubes, Alexandra police are suggesting signs need to be installed warning of the river's dangers.
However, an Alexandra Search and Rescue adviser believes common sense and personal responsibility are required to prevent another incident on the river.
There have been two similar incidents there.
"It's only a matter of time before we don't have a successful outcome on this patch of river," Alexandra area search and rescue adviser Adrian Dance said.
Sergeant Ian Kerrisk, of Alexandra, said the five boys and a girl, aged between 10 and 14, left the Ophir bridge about 3.30pm on Monday to float to Galloway.
Their parents had dropped them off and had organised to pick them up later.
The group had no lifejackets, warm clothing, means of communication or food.
"To say they were ill-prepared is an understatement. It was a silly idea that could have cost lives," Sgt Kerrisk said.
The group was unaware that while the river was calm at Ophir, about 1.5km down it entered a rugged gorge.
When the children failed to arrive, their parents called emergency services about 7pm and a helicopter was sent, finding them together in the gorge.
They were then taken by helicopter to the Chatto Creek Tavern.
The helicopter was used because children were involved, light was failing and it was the quickest way to retrieve them, Sgt Kerrisk said.
"They were starting to feel sorry for themselves, but they were in good health."
Police had spoken to the parents about the lack of lifejackets and the children about their behaviour, Sgt Kerrisk said. No further action was planned.
He hoped to liaise with the Central Otago District Council, search and rescue and community boards to see if installing warning signs was appropriate.
"Obviously, from previous incidents, people are not aware there is a significant change in [the nature of] the river."
In another incident, adult kayakers had become stuck and had begun to walk out when searchers met them.
Mr Dance said the area was becoming more popular, thanks to the rail trail, but people did not seem to make an effort to find out the conditions before they entered the water.
"People don't look at maps to check out where they are going . . . [yet] it's common sense."
