A big rescue effort was mounted in Otago last night after two paua divers were swept out to sea by a rip.

A member of the public saw the men in difficulty near Bird Island off Tomahawk Beach, Dunedin, and called 111 about 8.30pm.

A search for the pair was started involving two helicopters from the Otago Rescue Helicopter Trust, the Dunedin water rescue squad and lifeguards who launched two rescue boats from the St Kilda Surf Club.

The divers, aged 43 and 26, were in the water for about an hour before they made it to shore by themselves.

Police spokesman Sergeant Nathan White said they were uninjured but thankful for the assistance they received.