Private Ross disappeared under the water and his body was found a week later.
The family of the soldier believes he was unable to inflate his life jacket after falling into Lake Moawhango near Waiouru because he was unconscious after being hit by the butt of his gun in a freak accident.
Private Ross, 29, had handed in his notice to the military only weeks before he drowned in the lake during an army exercise on September 25.
His uncle, Jack Rogers, who trained Private Ross as a plumber before he joined the military, said his nephew planned to return to his Auckland home in November and back to work in the trade he loved.
"The military was really good for him in that it gave him some disciplines that he kind of needed in his life to keep him on track," Mr Rogers said.
"It had just given him some guidance and he thoroughly enjoyed that but his passion was always plumbing."
Private Ross was buried in the cemetery at St Stephen's Church, Pampuria, after a funeral at Te Paatu Marae in Northland on Monday.
In a eulogy at Private Ross's funeral, Major Brad Taylor told how the soldier was the military's "go-to guy" for plumbing problems.
Even during his service in East Timor, Private Ross was on hand to unblock toilets or repair showers, Mr Rogers said.
Major Taylor said at Private Ross's funeral that his decision to leave the army had been disappointing and the option of awarding him a commission had even been discussed.
"You have truly been a great soldier and a friend to all. Once a soldier, always a soldier," he said.
Private Ross's cousin, David Barrington Rogers, described him as a humble, passionate and motivated man.
"The army gave him a pride of place, of purpose and of self. Your special ability to touch our hearts will be greatly missed" he said.
Investigations by the military and the coroner will establish the cause of Private Ross's death.
Conditions "weren't ideal" and there was a "moderate chop on the water" when Private Ross fell overboard.
Mr Rogers said his nephew's face was "very badly" bruised and swollen after falling from the inflatable boat and his comrades on board could see blood streaming from him in the lake.
"They were yelling at him to pull his rip cord on his life jacket but of course there was just no response ... we assume he was obviously unconscious," Mr Rogers said.
"He was a very competent swimmer, he could tread water quite competently.
"The family accepts it is going to take time [to investigate his death]."
Mr Rogers said the support from the military and the general public had been overwhelming.
Navy divers spent days searching for Private Ross before his body was discovered by sonar on October 5 in an area 45m deep.
His family was supported by staff at the Waiouru Military Camp, where they waited anxiously for news.
Mr Rogers said a company had donated a casket for Private Ross's funeral and a design business created a unique Maori pattern to cover the coffin.
"There's been some tremendous support coming through and it's been quite overwhelming," Mr Rogers said.
A Defence Force spokesman said he could not comment on the investigation while it was subject to a Court of Inquiry.
- By Kieran Campbell of APNZ
