Dean Adrian Mitchell Thomas (57) died after he was found unconscious in the water near Shag Point by a friend before being brought to shore.
His son, Leon Porter-Thomas, told the Otago Daily Times his father was a keen outdoorsman who loved mixing with people from all walks of life, and a dedicated family man.
"He was probably dangerously friendly. He would introduce himself to anybody. He had a lot of friends and was probably over-dedicated to family. He would drop everything in a heartbeat to be with family, even if it was on the other side of the world. He was always there to support anybody who needed it.
"He was a hunter-gatherer kind of guy and loved his hunting, fishing and spearing."
He hoped his father's death would act as a reminder to people that even the most experienced divers were not immune to the dangers of the ocean.
"We want people to learn from what's happened and for people to know they should not go diving on their own, no matter how experienced they are. Dad was diving solo for four decades ... Anything can happen."
Sergeant Blair Corlet, of Oamaru, said Mr Thomas' friend performed CPR for several minutes before first responders arrived at the scene and took over.
Despite attempts to revive him, he was pronounced dead at the scene a short time later.
A police spokeswoman said emergency services were called about 5pm to reports of a person unconscious in the water.
It is understood conditions on the water were calm at the time.
A Fire and Emergency NZ spokesman said fire, ambulance and police attended the scene near near SH1 between Hampden and Palmerston.
Mr Thomas' death has been referred to the coroner.
He will be farewelled at a service at the crematorium chapel at Andersons Bay Cemetery in Dunedin at 10.30am today.
