One person is missing after a fishing boat carrying three people overturned on the Waitaki River.
The incident happened about 11am but the alarm was not raised till several hours later, after two survivors made it to shore then trekked "some distance" to find help.
A helicopter and four jet boats are now searching for the missing person.
A police spokeswoman said emergency services were called to the scene about 2.25pm after it was reported the boat got into trouble on the northern side of the river in the Black Point area, about 53km northwest of Oamaru.
