Ordinary Diver Macdonald, who moved to Taupō with his family from South Africa nine years ago, was deputy head boy at Tauhara College, as well as captain of the school's First XV and First XI.
He was inspired to join the RNZN in Year 9, when a recruiting bus came to the college.
He said it was a proud moment to reach the end of the course and graduate.
"They break you down and take you to some tough places in yourself, then build you back up. It's awesome. We love a challenge – it's what we signed up for."
He liked the RNZN because he related well to team environments and the organisation was full of passionate people of all kinds, he said.
"The navy has lots of effective people with different personalities, different backgrounds, getting through tasks as quickly as possible."
The hardest part of the course was the mental challenges, he said.
"You have to find a way to push through mentally, as well as helping your classmates who need support while you are struggling as well.
"You need to be precise with everything you do, in order to save time and keep track of everything. I'm a bit too particular in trying to do things perfectly, so it was learning to find a balance."
Macdonald's parents, Malcolm and Caron, are justifiably proud of their son.
"He was straight out of school and we thought his choice was fantastic. We supported him 100 per cent," Caron said.
He was keenly missed during his first five weeks of training, with letter writing the only contact allowed, she said.
"We're a really tight-knit family, and he was a real presence at home. But we knew he was doing the right thing."
