"This is just terrible and really tragic," he said of the latest fatality. "They were diving for the tangi for our kuia Emma Rogers."
The fact Mr Gage was diving to gather food for a tangi was a double tragedy for locals.
Mrs Rogers was well known in kapa haka, as a performer, judge and founder of the nationally successful Te Whanau a Apanui kapa haka group.
Mrs Rogers was a foundation member of Nga Puna Waihanga, the national body of Maori artists and writers. She was also committed to revitalising te reo Maori and was an acknowledged authority on the Ringatu faith and founder, Te Kooti Arikirangi Te Turuki.
Mr Gage was the nephew of Te Whanau a Apanui tribal leader Rikirangi Gage and his father Hori Gage works at Te Runanga o Te Whanau - the tribal authority for Te Whanau a Apanui.
Mr O'Brien, who also runs a fishing charter, said Mr Gage went diving for kaimoana straight off the beach at Omaio with a few others.
"He disappeared and his mates couldn't find him - it was a bit paru (dirty) and murky."
The alarm was raised and Mr O'Brien along with several other boat owners searched for the rest of that day without success.
"Early next morning some local boys went out at about half six in the morning and at about 8am they found him not far from where he disappeared.
"It was very tragic. He was a really nice young guy with a couple of tamariki (children)."
Mr O'Brien said Mr Gage had being doing a civil construction course.
"He was getting his tickets and learning to drive diggers and rollers. He was upskilling himself and trying to make things better."
Conditions were not that rough when Mr Gage was diving and Mr O'Brien said he was not discounting the possibility of health-related issues although that was not yet confirmed.
The matter has been referred to the coroner.
Tributes are flowing in for Mr Gage on Facebook and his funeral was to be held today in Omaio.