“I’m a professional engineer so I didn’t feel like enlisting, but my number got called up so I did go in,” he said.

After deferring his national service for six months to finish his degree, the now-Canberra resident was deployed to Vietnam in August 1969 for a year.

As part of his tour of duty, Mr Costmeyer served his time as part of the 17^th Construction Squadron and was based out of Nui Dat and Vung Tau.

“We were mainly involved in building roads and bridges as well as repairing villages,” he said.

“We were in the repair business, rather than the destruction business."

The squadron consisted of several hundred people involved in the rebuilding effort, and they also cleared areas of landmines as well as rebuilding many villages ravaged by the war.

“We were able to demonstrate to the local population we weren’t there to destroy, and that we were there to help and overcome their adversity,” Mr Costmeyer said.

While the Vietnam veteran wasn’t actively on the front line during the conflict, his squadron often came under attack.

“We were fired upon on a number of occasions. It wasn’t a wave of people but sniper fire and that sort of stuff,” he said.

Like many other Australians who served in the conflict, Mr Costmeyer said he received negative reactions from civilians after returning home.

“Over the years, it did become more normalised but it took many years, and we came back as changed people,” he said.

“Instead of coming back as heroes, we were shunned, and we thought why did we spend a year of our lives fighting overseas?”

Following his return, he continued to serve in a civilian role in the Department of Defence, as well as volunteer for more than 30 years with the Kambah Lions club.

This Anzac Day, the Vietnam veteran will be in Auckland.

“I’m not one for marching, but I will attend a service as it’s an important day,” he said.