Family of missing surfer thanks NSW locals

The family of an Irish surfer who disappeared in waters off northern NSW has thanked rescue teams and the local community.

Twenty-year-old Stuart Butler got caught in a rip at a beach near Byron Bay on Saturday while surfing with two mates.

Search teams spent the weekend scouring the waters off Tallows Beach for Mr Butler.

"We'd like to say a huge and heartfelt thank you on behalf of Stuart's family both here and back in Ireland for the support we have received from the local community," a family spokesperson said in a statement on Wednesday.

"In particular Mr Butler's relatives thanked Byron Bay and Tweed Heads police and surf rescue crews.

"We are full of hope that he will be returned to us and ask all to keep him in their thoughts and prayers."

Mr Butler's friends, a 26-year-old man and a 20-year-old man were both assisted from the area by rescuers on Saturday, police say.

Their statement came as a large search continued on Wednesday for a Swedish exchange student who went missing after going into the surf at Smoky Cape Beach near South West Rocks on the NSW mid north coast about 5pm on Tuesday.