Eight people are missing after a fishing boat sank north of Stewart Island.
Police in Invercargill say one person has been pulled alive from the water after the Easy Rider capsized at midnight Wednesday.
The survivor was rescued at 6.10pm Thursday evening from the Foveaux Strait after clinging to a petrol can for 18 hours.
Police say the Bluff and Riverton Coastguards, local fishing vessels and Southern Lakes helicopters are involved in the search.
It is being coordinated by the Rescue Coordination Centre with the Invercargill Police Search and Rescue squad.