ABOARD THE HMAS ADELAIDE >> At sea dozens of miles south of Oahu, one of Australia’s largest warships is practicing a role that’s becoming increasingly vital in the islands and nearshore waters that define the Pacific: the ability to get troops, equipment and supplies to shore when a harbor isn’t available.

The 754-foot amphibious assault ship — a downsized aircraft carrier — has deck space for six helicopters and a lower well deck that can launch landing craft.

Aboard on Saturday were 14 tanklike amphibious assault vehicles operated by Marines from Kaneohe Bay who are part of a 700-strong task force that will hit the beach at Bellows and Pyramid Rock later this month during ongoing Rim of the Pacific exercises, officials said.

Australia’s Defense Department said the Adelaide and sister ship Canberra are at the center of a strengthened amphibious capability.

The U.S. Marine Corps is the undisputed master of amphibious operations, but since 1981 Australia has been developing its own capability for power projection and “soft power” diplomacy assisting other nations in times of emergency.

The strategic re-balance to the Pacific “creates a need for deep, sustained and carefully crafted relationships,” the Center for Strategic and International Studies said in 2013.

U.S. Indo-Pacific Command’s “focus on reducing the likelihood of conflict makes relationship-building a top priority” at a time when China has made a similar calculation — launching the hospital ship Peace Ark in 2008, the center noted.

U.S. allies Australia and Japan are among countries adding to their amphibious capabilities to counter China. The United States, Australia, Indonesia and the Philippines have amphibious ships in this year’s RIMPAC.

Capt. Jon Earley, commander of the Adelaide, said Australia’s amphibious capability is “jumping ahead in leaps and bounds.”

“We just recently certified a number of our amphibious forces in an exercise back in Australia called the Sea Series, and now we’re here at RIMPAC trying to achieve different aims and objectives in terms of interoperability with our U.S. friends,” Earley said.

An amphibious force gives the Australian government versatility, he noted.

“Certainly in Australia’s case, when you look at threats that are around Australia right now, really, one of the biggest ones we face are environmental disasters” such as volcanoes, tsunamis, typhoons, hurricanes and earthquakes, Earley said.

In the absence of an airport or seaport ashore, “we can bring vehicles, aid, support, people and other aid organizations to help — so that’s where Australia is going with it. That’s the main focus at the moment,” he said.

Aiding that mission is a 50-bed hospital with an operating room.

The ship has wider hallways and stairs than American warships. And beer is available on board.

Lt. Col. Doug Pashley, the embarked forces commander, has 150 2nd Battalion, Royal Australian Regiment soldiers, the Army’s dedicated amphibious support unit, with U.S. Marines and Japanese, Tongan, Sri Lankan and Malaysian troops rounding out the task force of 700.

On Saturday the task force was still conducting live-fire exercises at Pohakuloa Training Area on Hawaii island.

“That’s what the first couple weeks of the exercise have been all about: working together to iron out many of the wrinkles that will come up” during more complicated amphibious operations, Pashley said.

A U.S. Navy SH-60 Seahawk helicopter practiced landings on the Adelaide’s 664-foot flight deck, with larger Marine Corps CH-53 Super Stallions expected to do the same on Sunday, officials said.

Cpl. Marco Martinez, 22, one of the Marines on the Adelaide, who is with the Combat Assault Company at Kaneohe Bay, will be one of those heading out in a 31-ton amphibious assault vehicle.

Arriving on the Adelaide with the tracked vehicles “was a little bit different experience compared to the American ships in the way it sits in the water and the way they actually lower it,” the Texas man said. “The Adelaide actually lowers itself and ballasts into the water as opposed to American ships where they have a ramp and we have to drive up into it.”

On the Australian ship “it’s much easier. We can just float into the ship instead of having to drive up,” he said.

That means the Marines can also float out — as opposed to on American vessels where the vehicles plop into the water and can momentarily submerge.