In failing light, members of local fire brigades safely plucked the pair from the river on Monday.
Emergency services were alerted about 5pm after a man was swept away while attempting to cross the river about 300 metres downstream from the confluence of the Buller and Inangahua rivers.
It is understood the pair, both New Zealanders, were part of a group staying at a nearby Airbnb.
Senior Sergeant Mark Kirkwood, of Greymouth, said the man was fully clothed with no lifejacket. A second man tried to initiate a rescue, but while the first clung to a rock, his would-be rescuer ended up stuck on the same rock with him.
A full rescue response was launched, including the Nelson rescue helicopter, Buller Surf Rescue, Reefton police, Inangahua and Reefton volunteer fire brigades and an ambulance.
The Greymouth Star understands a member of the Inangahua brigade is involved with a nearby rafting company located further up the Buller Gorge, and a bystander said the man was able to use a craft to take him and three other fire crew to the stricken men, just as it was getting dark, about 5.45pm.
Conditions in the river were considered cold and with "a wee bit of a fresh in it".
"One of the guys had been in the water a lot longer and his mate had swum out to pick him up. He said the crew in the raft were able to pull the men out of the water and take them up to the waiting St John ambulance, where they were treated and warmed up," a bystander said.
The witness said the rescue occurred just as Buller Surf Rescue and the Nelson helicopter arrived on the scene.
The men were very lucky - "it could have gone the other way".
Snr Sgt Kirkwood was full of praise for everyone involved: "Inangahua FENZ did very well - it was all hands to the pump and a good job all round".
"The Buller River is one you certainly have to respect, and people should be very careful trying to cross rivers fully clothed."
The rescued pair were "very cold, but very appreciative".
- By Meg Fulford
