In $20 rafts, the group launched into the flooded Clutha River at the Outlet of Lake Wanaka last week, bound for the Red Bridge at Luggate.
They were employees of a building firm with branches in Auckland and Wanaka.
One young man was soon stuck in a willow tree upstream of the Albert Town Bridge.
The other 13 eventually made it all the way to Luggate, although one was swept even further downstream before being able to get out of the river.
There were no casualties, but Mr Black said he was disappointed by the group’s decision-making.
‘‘Some of them are local guys, too, which makes it even worse because we’ve been on about the dangers of the high river [and the need] to keep off it.
‘‘How we didn’t lose someone, I don’t know.’’
Mr Black paid credit to Patrick Perkins, of Go Jet, who, along with Wanaka harbourmaster Craig Blake rescued the man from the tree.
The man, in his mid-20s, had cuts and scrapes and was ‘‘quite shaken’’, Mr Blake said.
‘‘From Auckland he was — never seen our river before — but the people he was on the river with had done it many times and said: ‘It’ll be fine’.’’
Mr Blake usually patrols using a jet ski but had a warning about the Clutha in flood. It was ‘‘not a pleasant river — very, very powerful, lots of standing waves ... and not particularly safe’’.
A helicopter and search teams were about to be called when the last two in the group arrived at the Red Bridge.
