Trampers are being warned to stay together after two hikers were found to have drowned after separating from their groups in Mount Aspiring National Park.
A coroner has found Brock Oliver, 42, and Allison Willen, 20, died in separate accidents while hiking on the popular South Island mountain earlier in the year after becoming separated from their parties.
"The message for trampers is clear. Keeping a party together enhances the decision-making process," Coroner David Crerar said in one of the findings.
Ms Willen, a visitor from the United States, was climbing the Gillespie Pass with two friends on April 25 when she fell behind amid heavy rain and wind.
She failed to turn up at their destination hut later in the night and her body was found in the Young River a week later.
Mr Crerar said Ms Willen was found to have suffered a head injury before drowning, suggesting she may have slipped and hit her head.
He said it was likely with more experience, her companions would have been wearing correct clothing for the weather conditions, meaning they would not have had to leave her behind.
Mr Crerar called the death "disturbingly similar" to another he had reviewed.
Brock Oliver, a Wellington-based editor, died on January 4, after becoming separated from his party and slipping into the Wilkin River, in the Mount Aspiring National Park.
Mr Oliver decided to return to the group's campsite alone, opting to cross the river instead of going down the track.
The coroner said it appeared Mr Oliver either slipped or was pulled in by the water. His body was found downriver on January 22.
"Had Mr Oliver stayed with the group and travelled via the track, this fatality would have been avoided," the Mountain Safety Council said.
The coroner warned groups to stick together in order to make stronger decisions.
He did not hold Mr Oliver's companions to blame, saying he made the decision to go alone.
In both cases, there was no evidence to suggesting the Department of Conservation had failed to give the hikers proper advice or help.