Rim of the Pacific exercises went out with a bang.

Ten amphibious assault vehicles launched from the USS Essex churned through the surf Wednesday and came ashore at Pyramid Rock Beach at Marine Corps Base Hawaii at Kaneohe Bay.

Hawaii-based Marines and soldiers from Tonga, Malaysia and Indonesia poured out of noisy CH-53E Super Stallion helicopters and assaulted a mock village, firing blanks.

And Australian soldiers advanced on pop-up targets at the Ulupau Crater range on the base, firing live rounds as 60 mm mortars looped overhead and exploded down range.

The final tactical phase of RIMPAC ended Wednesday. Most of the 40 participating ships will return to Pearl Harbor, and the visiting forces will have a few days to unwind — and spend a bit more money as tourists in Waikiki.

All that’s left of RIMPAC 2012 are final meetings and after-action reviews.

A total of 25,000 personnel, 40 surface ships, six submarines and more than 200 aircraft from 22 nations participated in or observed this year’s RIMPAC, the world’s largest international maritime exercise.

Col. Nathan Nastase, who commands the 3rd Marine Regiment at Kaneohe Bay, but also headed up the 2,200-troop multinational contingent that was part of a Special Purpose Marine Air-Ground Task Force during RIMPAC, summed up the need for the big interoperability exercise.

"It’s obvious the Pacific is a huge area with a lot of nations, so there’s just no way we could do really anything without probably marrying up with partner nations — so this is the way that we figure out how to work together," he said.

Wednesday’s beach and helicopter assault was the culmination of the biggest ground portion of RIMPAC. Eight nations — Canada, South Korea, Malaysia, Indonesia, New Zealand, Australia, Tonga and Mexico — participated alongside Hawaii Marines in the amphibious exercises. Japan was an observer.

The task force’s final scenario included coalition troops coming ashore to aid island country "Green" with stability operations after it experienced conflict with another island nation called "Orange," and the United Nations asked for multinational help, officials said.

On Saturday, Marine task force troops, heading in from the amphibious assault ship Essex, conducted a noncombatant evacuation of U.S. and other coalition civilians from country Green at Marine Corps Training Area Bellows, Nastase said.

On Tuesday, a helicopter assault into the northern part of country Green resulted in the destruction of an improvised explosive device factory, he said.

Nastase said the other nations want to learn from the Corps’ ability to arrive from the sea with air and ground forces.

"This demonstrates exactly what is the strength of the Marine Corps — our ability to be expeditionary (and) to come from the sea, meaning we don’t need to have a relationship (with a country) or an established port," he said. "We can project forces ashore that can conduct, frankly, any mission."

Lt. Tom Moore, 27, a platoon leader whose 33 soldiers are part of the 1st Battalion, Royal Australian Regiment, said "it’s different" working alongside the troops of nine other nations.

"You learn a lot about differences in culture and nations and different ways of doing things — in particular living in close quarters on a ship with them," he said. "So we learned quite a bit about them, and it’s good to do that to understand the differences between our nations and also our armed forces."

Hawaii "is great," he said, adding, "We haven’t been able to see as much as we’d like because we’ve been training."

The Australians had a few days of free time at the beginning of RIMPAC, and they’ll have a few days at the end.

"We’ve just been doing as much touristy sort of stuff as we can — buying a lot of equipment from the military stores, which we don’t have in Australia, and just hanging out and nightlife stuff. Enjoy your food, enjoy your drink," Moore said.