"I am drawn to companies with altruistic purposes," he said.
One of his first rescue operations including searching for a missing 14-year-old autistic boy.
"It was a cold Canterbury winter's evening, and this particular guy did not like to wear too many clothes," McOnie said.
The search lasted for about three or four hours before one of the search dogs found the boy curled up under a pine tree.
"I would hate to think what would have happened if the team hadn't been there looking for him."
McOnie said he had seen the best and worst of humanity working in both the military and LandSAR New Zealand.
"What I see in the volunteers is the best in humanity. Without the volunteers land-based search and rescue wouldn't exist."
There were 61 LandSAR groups throughout New Zealand with different teams specialising in cave, alpine, or water search and rescue as well as the search dogs. On top of that, there were about 3500 volunteers all over New Zealand.
"These guys are professionals in their own right, and they are very good at what they do."
Volunteers learned different search methods for different search and rescue operations, McOnie said.
"For example, searching for someone who was quite responsive and was looking for help is quite different to looking for someone who was hypothermic and curled up under a bush."
Volunteers also learned tracking methods to be able to follow someone's path.
"To simplify it, you are following someone's footprint to work out what they were doing, where they are going, what they might have with them."
McOnie said there were more than 700 people who were assisted in close to 500 search and rescue operations last year.
"Year on year it is increasing. Ninety-three of those are New Zealanders."
McOnie said there were very few unsuccessful search and rescue operations when searchers were unable to find a missing person - alive or dead.
"When you rescue somebody, and you get them out and save them from the situation they are in, that is hugely rewarding.
"At the same time, when it is a recovery [of a body], that is still a success because you at least get closure for the family."
McOnie said people reacted in different ways to different search and rescue operations, but volunteers were offered plenty of support to help overcome any emotional impacts.
The most common mistakes people made when they found themselves lost was not being prepared.
"The Tongariro Crossing is a known hot spot because people underestimate the altitude they are climbing too."