Two men spent about 15 minutes in the water in Fiordland this evening before other boaties came to their rescue.
The fishing boat, with two men on board, overturned about 5.15pm in Chalky Inlet, Senior Sergeant Dave Raynes said.
There was three other boats in the area who came to their aid.
"They'd been in the water a short time, about 15 to 20 minutes, so that was very lucky that they had been found," Mr Raynes said.
They were being transported to shore where a helicopter and paramedic and doctor were waiting for them.
It was not known what caused their boat to overturn.