U.S. and Philippine Marines Strengthen Maritime Fires Interoperability During ACDC 26.3

MANILA, Philippines – Rain hammered the roof as U.S. and Philippine Marines studied digital maps, target graphics and fire support plans spread across screens and whiteboards inside a command post at Marine Barracks Rudiardo Brown, Fort Bonifacio. Moments later, a call echoed across the room: “Attention in the fires and effects cell.” A string of coordinates followed as Marines from both nations worked through a simulated fire mission, refining the processes that enable combined maritime fires operations.

The Marines were participating in Archipelagic Coastal Defense Continuum 26.3, a bilateral training event conducted from May 25 to June 4, 2026, that brought together U.S. Marines with Air Naval Gunfire Liaison Company Detachment-North, Marine Rotational Force–Southeast Asia, I Marine Expeditionary Force, and Philippine marines with the Coastal Defense Regiment. The training enhanced interoperability between the two forces and supported the Philippine Marine Corps' Archipelagic Coastal Defense Concept.

Archipelagic Coastal Defense Continuum is a series of bilateral training activities and subject matter expert exchanges that support Philippine Marine Corps modernization efforts and strengthen combined readiness between U.S. and Philippine forces. During ACDC 26.3, ADET-N integrated with the Coastal Defense Regiment and 4th Marine Brigade to conduct fires and effects training focused on maritime defense and fire support coordination. As I MEF’s forward command element in the Philippines, MRF-SEA enables recurring engagements with the Armed Forces of the Philippines that strengthen interoperability throughout the year.

“As we celebrate the 75th year of the U.S.-Philippine Alliance, MRF-SEA, I MEF, provides a forward presence that enables Marines from both nations to train together, build interoperability and strengthen our combined readiness,” said U.S. Marine Corps Col. Robert S. Bunn, commanding officer, MRF-SEA, I MEF. “Every engagement, whether it’s a subject matter expert exchange or a major exercise, strengthens our interoperability and readiness while reinforcing a historic alliance that remains a cornerstone of a free and open Indo-Pacific.”

As part of ACDC 26.3, U.S. and Philippine Marines conducted bilateral fires and effects training focused on maritime targeting, fire support coordination and command-and-control procedures. The training supported Philippine Marine Corps modernization efforts while enhancing the ability of both forces to plan, coordinate and execute maritime fires as a combined team.

“Our mission is to integrate with our Philippine Marine Corps counterparts, share expertise and strengthen interoperability across the fires enterprise,” said U.S. Marine Corps Capt. Remington Mederos, an artillery officer and joint terminal attack controller with ADET-N. “Training together improves our ability to coordinate fires, exchange information and operate effectively as a combined team.”

The Coastal Defense Regiment plays a key role in Philippine Marine Corps modernization efforts by developing maritime fires capabilities and supporting the Armed Forces of the Philippines’ maritime defense objectives.

Classroom instruction combined with practical fire support rehearsals focused on maritime targeting, fire support coordination and command-and-control procedures. Marines refined processes for integrating fires across multiple platforms while improving their shared understanding of bilateral planning and execution.

“The professionalism and engagement of our Philippine Marine Corps counterparts have been outstanding,” said Mederos. “This training allowed us to share expertise, compare approaches and develop a common understanding of maritime fires and targeting procedures, which strengthens our interoperability as a combined force.”

Participating Philippine marines represented multiple specialties from across the Coastal Defense Regiment, including personnel assigned to maritime air defense and shore-based anti-ship missile units.

“This training is very important to us,” said Philippine Marine Corps Maj. Benjie Somuelo, a communications officer with the Coastal Defense Regiment. “Not all of us come from artillery backgrounds. Some of us are infantry, for example, so developing a common understanding of maritime fires is critical. Working alongside our U.S. counterparts helps us build knowledge and improve our ability to operate together.”

Marines from both nations developed a shared understanding of maritime fires planning, targeting and command-and-control procedures. The bilateral exchange provided opportunities to compare tactics, refine processes and build the professional relationships necessary to operate effectively as a combined force.

“Throughout the week, we strengthened our shared understanding of maritime targeting and fires integration,” said Mederos. “Each iteration builds familiarity between our units and improves our ability to work together during future exercises, contingencies and crisis response operations.”

Working shoulder-to-shoulder in the classroom and during fire support rehearsals prepares both forces for combined exercises and reinforces the longstanding partnership between the United States and the Philippines. Through recurring engagements such as ACDC 26.3, U.S. and Philippine Marines continue to improve interoperability, strengthen combined readiness and support a free and open Indo-Pacific.