Anzac Day: Sydney Harbour attacks foiled by those on watch

"I joined at 18, they wouldn't let you join before then," she said. "My brother was in the Army, he was overseas and I just thought well I can do my part too. I never thought of it as being an adventure."

After six weeks training in Ingleburn, in Sydney, she was deployed to various Sydney Harbour postings to record the movements of every single ship, with the city now on high alert after the submarine attack.

"I worked in headquarters where you watched the passing of the ships," Mrs Curtis said.

"I was down in the plotting rooms which was underground. You received the position of the shipping from outposts and you plotted the course of the shipping all around Sydney, we had to plot whether they were enemy ships. There was one person on the switchboard, one of the plotting table and that was about it."

She also plotted shipping movements from a posting at North Head, with her final six months working in ordinance at Scone in the NSW Upper Hunter.

Mrs Curtis, who is now aged 96 and lives at Narrabeen, on Sydney's northern beaches, said she has fond memories of her service and the friends she made there.

"It was serious, you weren't there for a laugh, but we did have lots of laughs," she said.

"Your work was quite serious and you had to be responsible, more so out at Cape Banks which was at La Perouse. I enjoyed it, it was good, the comradeship, OK there was lots of hard work, night shifts, but I enjoyed it."