Three British tourists should be made pay for the cost of being rescued from a handmade raft in Lake Wakatipu on Friday, Queenstown Lakes harbourmaster Marty Black said.
The cost of the rescue was between $1000 and $1500, he said.
"I question why the taxpayer should have to pay for their stupidity."
The trio built the raft using four tubes from truck tyres, bungy cords and duct-tape.
They set off for an overnight trip to Pigeon Island on Wednesday without any safety gear or life jackets, he said.
They spent the night in a Department of Conservation hut before heading back to shore on Thursday.
Waves and strong winds blew them to Pig Island, which has no hut.
"They only had light clothing, one wet sleeping bag, no food and no cellphone. It was just ridiculous."
Friends at the hostel they are staying at raised the alarm when they did not return.
A Doc officer spotted them paddling through the rain towards Queenstown on Friday morning, Mr Black said.
The Queenstown coastguard picked them up about 9.30am and brought them to Ngai Tahu wharf, where Mr Black gave them a "severe talking to".
Becky Wills (24), Amy Hurdiss, (24), both of Weymouth, England, and Michael Gribbin (32), of Staffordshire, England, told The Southland Times they had been woefully underprepared.
"We just weren't prepared for conditions that can change in the blink of an eye, and for the complete isolation out there," Mr Gribbin said.
The lake was calm when they set out and it took them one and a-half hours to paddle to Pigeon Island.
They had a good night on the island and had considered staying another night but left in the morning "to be safe", Mr Gribbin said.
After being blown to Pig Island, they had a tough night.
"We had no fire, our sleeping bags couldn't have got any wetter and all we had was green tea and honey," Ms Wills said.
"We were dizzy, delirious and hypothermia wasn't that far away."
After a night huddled underneath the raft, the friends paddled the raft through rain to get back to Queenstown.
Friends raised the alarm when they did not return on Thursday night and a search was mounted. A boat spent several hours searching in the dark and a helicopter was readied to join the search on Friday morning.
