On Tuesday two people activated their distress beacon after finding themselves in trouble in Fiordland.
The hunters had been separated from their inflatable boat and were in peril in a rapidly rising river.
Southern Lakes Helicopters assisted the pair, who Johnston said could have been in serious danger.
Johnston said distress beacons became crucial for hunters in trouble if they didn't have cell signal.
"If you feel that your life is in grave or imminent danger, you should first try to use two-way communications such as a phone or radio so that you can talk to emergency services," he said.
Mid-March to mid-April is a popular time for hunters, due to stags being more vocal than usual in the mating season.