Jake Bridson, of Heriot, died while free-diving at the popular Catlins snorkelling spot about noon on Sunday, after he became separated from a fellow diver.
Bridson was hailed a hero in 2015 after keeping a potentially disastrous scrub fire at bay while working as a farmhand.
In a death notice in today's Otago Daily Times, the family said he was "stolen from us too soon, doing what he loved''.
"Of all the special gifts in life, however great or small; to have you as our son, Jake, is the greatest gift of all.''
A celebration of his life would be held on Saturday in Middlemarch.
Otago Regional Rescue Helicopter chief pilot Graeme Gale said the drowning had been "sobering" for the rescue crew, and was a "terrible tragedy" for the victim’s family and friends.
"Everyone was out there having a great time and then tragedy strikes."
A small comfort was the rapid location of Mr Bridson, less than 100m offshore at the Owaka Inlet, which meant his body could be returned to his family to bring "some closure", Mr Gale said.
The helicopter crew included two water rescue staff and a paramedic. Mr Bridson was found by 1.40pm.
Police said he was not able to be revived and was pronounced dead at the scene.
In 2015 Bridson was working as farmhand near Clarks Junction in Otago when a fire broke out.
He and farm stock manager Jason Tisdall and farmer Jim Stevenson loaded a spray tank on to a ute and used water from it to keep the fire contained.
Speaking to the Otago Daily Times after the fire was extinguished, a soot-dusted and tired Mr Bridson said he was alerted to the fire by seeing the flames and the startled technician.
"I just seen it and I was like 'oh no'," the 17-year-old said.
"He [the technician] was head in his hands.
"We lifted up the spray tank on to the truck and drove down there and were fighting it with a spray tank
Wellington-based New Zealand Underwater Association president Tristan Reynard said he was not aware of the Catlins incident and expressed his condolences to the family of the dead man.
The association had launched a campaign this summer aimed at reducing diving accidents, following a recent upsurge in both numbers of divers and diving fatalities.
Water Safety New Zealand statistics show there were 11 diver fatalities in 2019, an increase on the five-year average of six underwater sport deaths a year.
"We’re seeing an increase in new divers and more people taking up things like spear-fishing, which doesn’t require scuba gear so can sometimes attract the less experienced into challenging situations.
"Talking in general, there are several precautions people can take to ensure underwater sport safety.
"Probably the uppermost of these, based on the coroners’ reports we review, is knowing your own personal limits and a group not diving beyond the limits of the least experienced member of the team."
Diving buddies needed to have confidence in one another before tackling challenging conditions, he said.
"Ocean currents in New Zealand are tricky and highly variable from place to place. I haven’t dived the Catlins, but understand there was an earlier incident not too far from this location."
In 2018, South Otago friends Mitch McPhee (23) and Malcolm Ward (51) died while diving for paua further south in the Catlins, in Purakaunui Bay.
Mr Reynard said the association offered an online safety checklist for divers and encouraged people to use it.
"We’ll review this case once it’s been before the coroner. It’s our aim to keep educating the diving community and eventually eliminate unnecessary deaths."
