Search and Rescue crews say a group of trampers rescued after 18 hours in the bush could have been picked up much earlier if they'd had an up-to-date beacon.
An Auckland man visiting Levin took his father and son on a day walk on Thursday in the Tararua Ranges behind Shannon.
They did not take a map and became confused, taking the wrong track.
Horewhenua Search and Rescue says a passing tramper lent the group a distress beacon, but it was an old model which is no longer picked up by satellite.
The three were eventually rescued late on Christmas Day, about 18 hours after the beacon was activated.
Search and Rescue says the incident should serve as a reminder to people to update from the old 121.5 version of distress beacon to the 406 version, which is monitored by satellite.