Police were notified at 10.10am that "a dragon boat or waka" appeared to be in trouble approximately 150 metres from shore.
A police spokeswoman said all six people involved in the incident were safely back on shore.
"Three of them [were] transported to hospital to be treated for possible hypothermia."
A St John spokesperson said three ambulances responded after notification of the incident at 10.14am.
All six people had moderate injuries, the spokesperson said.
"Three were transported to Dunedin hospital, the remaining three were treated at the scene."
An eyewitness said emergency services vehicles were still at the scene on Portobello Rd at Vauxhall about 10.45am, although the rescue effort appeared to be over by then.
"They weren’t rushing at that point.
"It looked like they had a rope out [and] just pulled in a boat."
It was initially reported that the boat had overturned.
St Clair Surf Life Saving Chairman Cam Burrows said by the time his team attended the scene, all those involved were already ashore and he believed the boat involved was part of the Otago division of Waka Ama.
Fire in Ice Outrigger Canoe Club president Brendon Timmins declined to comment.
