OFF THE COAST OF CAMP PENDLETON, Calif. — Top brass from nearly two dozen Pacific militaries got a first look at the Navy and Marine Corps' latest sea-basing operations during a symposium meant to boost partnership with forces from across the vast region.

Military leaders from 23 countries watched from a ferry as a trio of air-cushioned landing craft skimmed across the ocean and parked on a ballasted starboard deck of expeditionary transfer dock USNS John Glenn.

Linked just about 6 six feet from the John Glenn sat a multi-mission replenishment ship, the USNS GySgt. Fred W. Stockham. Its whose cavernous decks were packed tight with vehicles, combat and operational equipment and supplies.

The demonstration week's sea-basing showcased how the U.S. sea services can one of the Navy and Marine Corps' latest concepts to extend the reach of logistical support when military forces face limited or no access ashore. The sight of large ships so close together drew awe and curiosity from the senior military leaders of 23 countries attending the five-day U.S. Pacific Command Amphibious Leaders Symposium this week in San Diego.

"Our adversaries, they can't do this," said Maj. Gen. Richard Simcock, the 3rd Marine Division commander based in Okinawa, Japan, shortly after arriving on Glenn for the six-hour visit at sea.

U.S. allies and military partners can't exactly do it, either. But officials say future military operations are likely to involve more allies. That , just like today's, won't be done alone but instead will involve nations working and operating together jointly, officials say. And that requires a wide range of support.  and participating, depending on each nation's maritime warfighting and support capabilities. "How can they contribute?" Simcock said the overarching theme of the symposium was "how can they contribute?"

"They have tremendous pride in their nation, like we have of ours" he noted of his foreign counterparts. "If you give them an opportunity to show what they can do, they'll knock it out of the park."

Assault Amphibious Vehicles launch into the water with foreign military leaders onboard during the USPACOM Amphibious Leaders Symposium 2016 (PALS-16) at sea, near Camp Pendleton, Calif., on July 13, 2016. PALS brings together senior leaders of allied and partner nations from the Indo-Asia Pacific region to discuss key aspects of maritime/amphibious operations, capability development, crisis response, and interoperability. Twenty-two countries, including the U.S., are participating. (U.S. Marine Corps photo by Lance Cpl. Danny Gonzalez/Released)
Assault Amphibious Vehicles launch into the water with foreign military leaders onboard during the USPACOM Amphibious Leaders Symposium 2016 (PALS-16) at sea, near Camp Pendleton, Calif., on July 13, 2016. PALS brings together senior leaders of allied and partner nations from the Indo-Asia Pacific region to discuss key aspects of maritime/amphibious operations, capability development, crisis response, and interoperability. Twenty-two countries, including the U.S., are participating. (U.S. Marine Corps photo by Lance Cpl. Danny Gonzalez/Released)

Assault amphibious vehicles launch into the water with foreign military leaders aboard during the U.S. Pacific Command Amphibious Leaders Symposium 2016.

Photo Credit: Lance Cpl. Danny Gonzalez/Marine Corps

Ships have been sent over the years to support Marine Corps forces ashore conducting humanitarian or disaster relief operations, a demand military officials don't expect to ease. The ships on display here can be pre-packaged with gear and equipment that's tailored for a specific region.

The prepositioning ships can remain offshore and the vehicles and supplies can be loaded onto via barges or air-cushioned vehicles, as demonstrated with the John Glenn, and brought ashore to Marines.

"We want to put as much stuff on those boats as we possibly can," Simcock said. "It will be the most effective for a likely contingency."

Lt. Gen. Lawrence Nicholson, who commands the Japan-based III Marine Expeditionary Force, said the leaders discussed the need for interoperability during contingencies like humanitarian crises or natural disasters. The threat of destruction from tropical storms, earthquakes and tsunamis is an ongoing concern in the Pacific, so those types of missions forge "a common bond," he said. The leaders are also concerned about threats from civil strife and terrorism.

U. S. Marine Lt. Col. Koichi Takagi, Marine Attaché to Indonesia, translates a discussion on the Landing Craft Air Cushion to Brigadier General R.M. Trusono, Commandant of the Indonesian Marine Corps, at the USPACOM Amphibious Leaders Symposium 2016 (PALS-16) at sea, near Camp Pendleton, Calif., on July 13, 2016. PALS brings together senior leaders of allied and partner nations from the Indo-Asia Pacific region to discuss key aspects of maritime/amphibious operations, capability development, crisis response, and interoperability. Twenty-two countries, including the U.S., are participating. (U.S. Marine Corps photo by Lance Cpl. Danny Gonzalez/Released)
U. S. Marine Lt. Col. Koichi Takagi, Marine Attaché to Indonesia, translates a discussion on the Landing Craft Air Cushion to Brigadier General R.M. Trusono, Commandant of the Indonesian Marine Corps, at the USPACOM Amphibious Leaders Symposium 2016 (PALS-16) at sea, near Camp Pendleton, Calif., on July 13, 2016. PALS brings together senior leaders of allied and partner nations from the Indo-Asia Pacific region to discuss key aspects of maritime/amphibious operations, capability development, crisis response, and interoperability. Twenty-two countries, including the U.S., are participating. (U.S. Marine Corps photo by Lance Cpl. Danny Gonzalez/Released)

Marine Lt. Col. Koichi Takagi, Marine attache to Indonesia, translates a discussion on the Landing Craft Air Cushion to Brigadier General R.M. Trusono, commandant of the Indonesian marine corps.

Photo Credit: Lance Cpl. Danny Gonzalez/Marine Corps

The 73 military officers attending PALS — along with nearly 100 U.S. troops — military officers, staff and civilian experts hail from nations large and small. Some of the countries participating included Australia, Bangladesh, Canada, Chile, Colombia, France, Indonesia, Japan, Malaysia, Maldives, Mexico, New Zealand, Peru, Philippines, Republic of Korea, Singapore, Sri Lanka, Taiwan Thailand, Tonga, the United Kingdom and Vietnam. Commandants and top commanders from the marine corps in Chile, Colombia, Indonesia, Maldives, Peru, Philippines and Thailand also attended.

The focus of the symposium, which wrapped up Thursday, is about building relationships, Nicholson said.

"[There are]That's 23 different ways to look at the problem and get different perspectives and points of view, and that's invaluable," he said.

A broader goal, several participants mentioned, is to foster stronger ties that will lead to more interoperability, training and exercising together. That's especially important for the Pacific nations in the midst of strengthening their maritime and amphibious capabilities. 

Several Pacific Rim nations are in the midst of building or strengthening maritime, coastal or amphibious capabilities. "For us, iIt's important that when they get off the beach head, in an expeditionary model, they can work together," said Col. J.P. Davis, Canadian military attache to the U.S. Army at the Canadian embassy in Washington. "Interoperability between both organizations is paramount." 

This week's symposium by Fleet Marine Force Pacific had more attendees than last year's inaugural meeting held in Hawaii concurrently with joint exercise Culebra Koa 2015. Next year's event might be held overseas but officials have not announced the date and location.