Bernard Rhodes, the grid master at the Waiheke Boating Club, which is situated just metres from the site of the fatal fire, said Mr Brady was "a good sort" despite his problems with alcohol.
"I always got on fine with him. He was an intelligent guy," Mr Rhodes said.
Mr Brady had formerly had a career in architecture - having written his Diploma in Landscape Architecture thesis at the University of Canterbury, which was on fountains in urban landscapes.
However, "10 or 15 years ago" he lost his wife to cancer and "he gradually went downhill". He bought an historic boat, the Kate, because "he said he needed a project", Mr Rhodes said.
"[But] gradually he became an alcoholic. And when he drank he became abusive."
Mr Brady had had some run-ins with the police and had at one point been made to move his boat by the council.
"He was getting drunk and aggressive and would get in fights with other drunk boaties," Mr Rhodes said.
The former architect had tried to renovate the 100-year-old Kate, but when it became too much for him he sold it to the Waiheke Working Sail charitable trust, of which Mr Rhodes is a trustee.
The trust is repairing the Kate to sail as a training ship for Waiheke youth.
Mr Rhodes was able to buy another boat away from the main liveaboard community, in Anzac Bay.
Mr Brady, Mr Walker and others living on their boats on the island were often misunderstood, Mr Rhodes said.
"These are people that have been really unfortunate in many ways," he said. It was easy "to rubbish them".
It is believed that on the night of the fire the two victims had been drinking together on Mr Walker's boat.
Police have asked anyone who had been aboard his boat, the Countess, in recent weeks to contact Waiheke police on (09) 372 1150.
