He is also national director of the scout photography school and former chief instructor.
"I just enjoy working with young people," Mr Randles said.
He spent 20 years in the airforce before re-training as a teacher.
But despite his many hats, he said all of his activities seemed to tie together in one way or another and feed off each other.
"I think the main thing is I enjoy the outdoors."
He admitted it was a busy schedule with evening and weekend volunteering.
"There's not a lot of down time - if you talked to my wife, she'd say I'm never home."
Mr Randles is nominated for a Pride of New Zealand Award in the community spirit category.