· Species of killer shark to be identified

It was only two years ago that Zac Young turned his back on the party lifestyle to help others.

Full of promise and enthusiasm, the 19-year-old from Port Macquarie was able to use his own experiences and personal triumph to instil hope in other young people.

His death has left a NSW mid-north coast community in mourning.

Mr Young was surfing with his mates at Riecks Point near Coffs Harbour on Saturday when a shark attacked him.

Despite his friends’ heroic efforts to struggle with the shark and drag Mr Young to shore, he suffered massive blood loss and died.

Hundreds of friends and family descended on Grace Church at Port Macquarie to pay tribute to the much-loved teenager on Sunday.

Mr Young was remembered as a talented surfer and photographer, who was an intern with a Christian organisation called Youth for Christ, which works with at-risk youth.

Friend Lindsy Isaac, who helped get Mr Young back to shore, told reporters at the memorial it was the scariest thing he had ever been through.

“I can’t believe he is gone,” he told media.

Mr Young’s father Kevin revealed his son told his friends “I love you” as they tried to save him.

Daryl Carter, regional director at Youth for Christ, said that was just what Mr Young did.

“He would do that all the time,” Mr Carter told AAP following the service.

“He told me he loved me only on Friday afternoon.

“It’s pretty hard to comprehend a world without him.”

Through his role with Youth for Christ, Mr Young would talk to school students about values, the hurdles he had faced and how he overcame them.

Having turned his back on the party life about two years ago, Mr Carter said Mr Young made an impact on everyone he met.

“It’s a huge loss in terms of him and his story, but I think his story will keep living and impacting people,” he said.

Following the memorial service on Sunday, family and friends held a “paddle out” at a nearby beach and a minute’s silence in the ocean.

Tributes also flowed on Facebook.

“Zac was always looking out for others,” Brandon Erga, a pastor at Grace Church, wrote. “It didn’t matter if he was busy, he always had time for those in need. It didn’t matter who you were, Zac considered you a friend.”

Beaches remained closed in the Coffs Harbour area on Sunday as the search for the shark – thought to be a three-metre tiger shark – continued.

Forensic specialists will examine the bite marks on Mr Young’s body to determine the species responsible.

Local surfers say the reef break where Mr Young was mauled is known for shark activity, but Coffs Harbour police Inspector Joanne Reid said attacks were very rare.

“As far as sightings go, that sort of stuff isn’t always reported so it’s hard to say, but it’s incredibly rare,” she told AAP.

“In NSW itself, it’s rare. I think the last one was in WA.

“The community is very, very much in shock.”

Mr Young’s death follows a fatal shark attack at Gracetown in Western Australia last weekend.