One person is suspected to have suffered hypothermia and three others are being treated by St John staff after "several'' yachts capsized on Lake Aviemore in the Waitaki Valley this afternoon.
A police spokeswoman said police were called just after noon after reports of four yachts capsizing in today's annual Trust Aoraki Aviemore Classic.
She could not confirm the number of yachts that capsized.
But police, the coast guard and St John remained on the scene about 1pm today.
Timaru Yacht and Powerboat Club commodore Gordon Collister said he was not at today's race, and could not speak to the incident, but with a forecast northwesterly, conditions on the lake were likely to be "very unpredictable" making for "difficult sailing''.
The regatta was known for its high wind conditions.
However, the regatta, hosted by the Timaru club, typically attracted experienced sailors, he said.
