The value of the exercise, according to the U.S. officer overseeing it, lay less in the ships themselves than in what firing on them together revealed about the coalition doing the firing. Vice Adm. Jeff Jablon, who commands the RIMPAC 2026 Combined Task Force, said the exercise crystallized why the alliance-building underpinning RIMPAC matters in the first place.
“Watching our Sailors work side-by-side with partners from around the world, executing complex maritime events together, is the strongest reminder of why these relationships matter,” Jablon said. He added that the exercise offered concrete proof of what years of joint training produce. “SINKEXs are a prime example of the strength and readiness our partnerships create,” he said.
Naval and air units from Australia, Canada, Italy, Japan, New Zealand and Spain trained alongside the U.S. Navy, Air Force and Army throughout the exercise, working through targeting, tactics and live-fire procedures against a genuine surface target, a level of realism that simulated exercises cannot replicate. Military officials say that distinction is precisely the point: live-fire training against an actual hull sharpens a coalition’s ability to plan and execute complex strike operations under conditions that closely mirror real combat.
Republic of Korea Navy Rear Adm. Inho Kim, who served as RIMPAC’s Combined Force Maritime Component Commander, described the exercise as proof of a partnership whose depth goes beyond routine coordination. “The successful execution of multiple SINKEXs highlights the unbreakable bond and growing capability of our coalition,” Kim said, framing the achievement in terms that extended beyond the tactical to the strategic. “Together, we are demonstrating a shared commitment to regional stability by developing tactics and skills in maritime operations,” he added.
None of it happened without careful preparation beforehand. Each SINKEX site is surveyed in advance to confirm the absence of people, vessels, aircraft and marine wildlife, with the exercises planned under the National Environmental Policy Act and conducted in accordance with Navy permits issued under the Marine Mammal Protection Act, the Endangered Species Act and the Marine Protection, Research, and Sanctuaries Act.
The two ships sent to the ocean floor carried substantial service records into their final missions. Mobile Bay, a Ticonderoga-class guided missile cruiser, was commissioned in February 1987 at the Alabama State Docks, homeported first in Mayport, Florida, and later with the U.S. 7th Fleet in Yokosuka, Japan, over a career that included support for Operations Desert Shield, Desert Storm and Iraqi Freedom, as well as humanitarian relief work following the 1991 eruption of Mount Pinatubo in the Philippines.
The cruiser was decommissioned in August 2023 after more than 36 years in service. Peleliu, by contrast, belonged to the Tarawa class of amphibious assault ships, among the largest amphibious warfare vessels ever built and frequently compared to a small aircraft carrier for its ability to launch aircraft from a flight deck atop a nearly 40,000-ton hull.
Commissioned in May 1980 and homeported in San Diego, Peleliu completed 17 deployments over its career, supporting combat operations during Desert Storm and Iraqi Freedom while also delivering humanitarian assistance after the 1991 Pinatubo eruption and the 2010 floods in Pakistan. It was decommissioned in March 2015 after 35 years of service, closing out a career that touched roughly half the globe.
Both ships’ final missions unfolded within an exercise of considerable scale. Some 30 nations are participating in RIMPAC 2026, contributing 30 surface ships, five submarines, 15 national land forces, more than 190 aircraft and 30,000 personnel across the Hawaiian Islands from June 24 through July 31, cementing its status as the world’s largest combined-joint maritime exercise.
That scale is by design, and organizers say the exercise’s real value lies less in any single event than in the cooperative relationships it builds among participating nations, ties the Navy considers essential to keeping global sea lanes safe and secure. This year’s edition, the 30th in a series dating back to 1971, was staged in large part to reinforce exactly that point.
