Two people are dead and three are recovering in hospital after a fishing boat capsized south of Bluff last night.
Fisherman's Shore Station marine radio operator Meri Leask said she received a call about 10.30pm from the owner of the fishing vessel Easy Rider.
The man and his family were camping at Caroline Bay on Ruapuke Island, in the Foveaux Straight, when he looked up to see people in the water near his vessel.
The skipper hopped in his dinghy and fished the survivors from the water, carrying the tired trio back to the safety of his camp.
His family looked after the three, who were "not in very good condition" after being in the water for more than four hours, said Ms Leask.
The survivors were "in shock" and barely talking once they made it back to dry land, she said.
"They'd been swimming for some time. Apparently the accident happened about 6pm last evening."
The group of five Southland men and women got into trouble when a wave hit their recreational boat near the island.
"I understand that a wave hit the boat and the boat overturned, it flipped the boat, and they all ended up in the water," Ms Leask.
The survivors were flown to Southland Hospital, and a large search operation was launched to find their missing companions.
The search party of two Coastguard boats, three fishing vessels and the Southern Lakes Helicopter combed the area to find the two bodies about three hours later, she said.
"My understanding is (they were found) on the beach at Caroline Bay in Ruapuke. They had been washed ashore."
All five members of the fishing party were wearing lifejackets, but had not used the radio to say they were heading onto the water.
The survivors are reportedly in a stable condition in hospital.
Ms Leask said there were few boating incidents in the area last year because local boaties were good at using the radio system to say they were headed out.
She warned boaties to check the weather before heading out, carry a radio and flare and always wear a lifejacket.