This time round, it was about saving lives - not perfecting their deadly shot.

For nearly 25 years, Singapore Armed Forces (SAF) soldiers have been using Exercise Wallaby in Australia to hone their battlefield steel.

But for the first time, they also incorporated a separate exercise to test how aid would be delivered in a tsunami-wrecked portion of the country's coastline.

The six-day Humanitarian and Disaster Relief (HADR) exercise dubbed Exercise Trident, began on Tuesday and imagines an undersea earthquake and a powerful tsunami which devastates long stretches of Australia's Queensland coast - a scenario eerily similar to the March 2011 disaster which afflicted Japan.

In the exercise play, air, land and sea units with more than 900 servicemen swing into action after the Australian Defence Force (ADF) accepts the SAF's offer of help.

On Tuesday, watched on by Defence Minister Ng Eng Hen and Australia's Assistant Minister for Defence Stuart Robert, SAF Chinook helicopters evacuated the injured to the navy's Landing Ship Tank (LST) RSS Resolution, and also dropped medical teams into the fictional town of Sam Hill.

Naval vessels ferried supplies to shore from the LST, even as a water purification unit was readied to provide relief to civilians.

Exercise Trident, in which 14 ADF personnel joined as planners, is also the first bilateral exercise in Exercise Wallaby's history, and the first time the SAF conducted integrated air, land and sea operations there.

Dr Ng, who returns to Singapore tomorrow, also observed a live-firing exercise and officially commissioned into action the SAF's upgraded Light Strike Vehicle Mark II.

The ongoing 65-day Exercise Wallaby which ends on Nov 30, involves about 5,200 troops this year and is the SAF's largest overseas exercise. It takes place in the rugged bushland of Shoalwater Bay Training Area, which is four times the size of Singapore.