"Carrying a registered PLB essentially removes search from search and rescue, drastically increasing the likelihood of a successful outcome."
Southern Lakes Helicopters spokeswoman Erin Robertson said the pair hadn't intended on taking a locator beacon, but were talked into it by the wife of one of the men.
"They had just been planning to take a radio, but there's no guarantee there will be reception, and given they were going to be away for a considerable period, if something went wrong it would be some time before anyone would be able to assist," she said.
The man was transferred to Invercargill by the rescue helicopter and is now recovering at home.