The 22-year-old was found with significant injuries, still dressed in his wetsuit, beside his car near the Coffs Harbour Surf Life Saving Club about 6.40am on Thursday.
Paramedics treated him at the scene before taking him to hospital, where he later died.
Coffs Harbour detectives on Friday were searching for the attacker, for whom a description has not been released.
Avenues of inquiry include whether the surfer came across someone breaking into his car, and what if any relation a confrontation at a second beachside area on Thursday morning had to the homicide.
"We've identified some items of interest at a campsite around the jetty area," Detective Chief Inspector Guy Flaherty told reporters on Thursday.
"This area may or may not be related but at this point we've declared a crime scene."
The surfer's uncle Ralph took to Sydney radio to pay tribute to his "lovely young" nephew.
"More than anything else, he just had a heart of gold, he really did," he told 2GB on Friday.
"A gentle, caring nature was his greatest asset. We're just broken."
The uncle also added his voice to calls to adopt Queensland 'wanding' laws that permit police to use hand-held metal detectors in public places to uncover concealed knives.
Named for a teenager stabbed to death on the Gold Coast, Jack's Law has taken more than 500 weapons off the streets since its passing in March 2023.
"How long do we have to wait here in NSW? This will save lives," Ralph said.
"He was just coming back from the surf, stabbed eight times. What on earth is going on?"
Premier Chris Minns, a fortnight ago, said he was looking at adopting the law in NSW after a spate of high-profile knife attacks that shocked Sydney.
Police, emergency services and transport unions have backed the change and decried the "appalling incidence of youth knife crime".
But the Council for Civil Liberties warned of a knee-jerk response to "violent and distressing but isolated" incidents and worried police would disproportionately search marginalised communities.
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