By Robbin Laird
Exercise Balikatan 2025, the 40th iteration of the annual U.S.-Philippine military exercise, marked a significant milestone in the evolution of U.S. Marine Corps littoral warfare capabilities in the Indo-Pacific region. Conducted from April 21 to May 9, 2025, the exercise showcased the debut of the 3rd Marine Littoral Regiment’s new rotational force concept alongside advanced unmanned surface vessel (USV) technologies from Maritime Tactical Systems (MARTAC).1
This combination of innovative organizational structures and cutting-edge autonomous systems represents a fundamental shift in how the Marine Corps approaches maritime security and coastal defense in contested environments.
The 3rd Marine Littoral Regiment’s New Rotational Force
The 3rd Marine Littoral Regiment (MLR), based in Hawaii, introduced the Littoral Rotational Force-Luzon during Balikatan 2025, establishing a forward-deployed presence in the Philippines. This new formation differs significantly from the Marine Rotational Force-Darwin in Australia, as it is led by the MLR rather than a traditional Marine Air-Ground Task Force. According to 1st Lt. Anne Pentaleri, the 3rd MLR public affairs officer, “When you think MLR, you think of the Philippines,” highlighting the unit’s strategic focus on the archipelago.2
The rotational force builds upon three consecutive years of training in the Philippine archipelago, focusing on littoral operations and coastal defense. The unit is scheduled to remain forward-deployed for both the spring Balikatan exercise and the summer Kamandag exercises, providing persistent presence in this strategically vital region.
NMESIS Deployment to the Philippines
One of the most significant developments during Balikatan 2025 was the inaugural deployment of the Navy-Marine Expeditionary Ship Interdiction System (NMESIS) to the Philippines. The 3rd MLR received this system in November 2024, and its deployment to the Batanes Islands represented a major milestone for the continuously developing U.S.-Philippines alliance.3
The NMESIS is a ground-based anti-ship missile system mounted on an unmanned vehicle platform, capable of engaging maritime targets at ranges up to 100 nautical miles with Naval Strike Missiles. U.S. Air Force C-130J Super Hercules aircraft from the 39th Airlift Squadron transported the system to Batan Island during the Maritime Key Terrain Security Operations event.
Lt. Gen. Michael Cederholm, the U.S. Joint Task Force commander, emphasized the system’s strategic importance: “We are expeditionary by nature, and training on the Batanes with our Philippine allies and the precision fires capabilities of the NMESIS advances our mutual maritime defense in an austere and geographically dispersed environment.” The Batanes Islands, located between Luzon and Taiwan in the Luzon Strait, represent critical maritime key terrain in the region.4
MARTAC Unmanned Surface Vessels
While the NMESIS deployment received significant public attention, the use of MARTAC unmanned surface vessels during Balikatan 2025 remained relatively low-profile, with public acknowledgment coming only in late May, weeks after the exercise concluded. U.S. Naval Special Warfare forces operated a MARTAC T38 Devil Ray USV at Naval Operating Base Subic on May 5, 2025. Photographs released by the U.S. Air Force showed a Naval Special Warfare Combatant Craft Assault towing the Devil Ray in front of Quay 7.5
The Devil Ray T38 represents a highly capable unmanned platform with impressive performance characteristics. The system can reach speeds up to 80 knots and carry payloads weighing up to two tons. The Devil Ray utilizes Starlink satellite communications for command and control, providing operators with reliable connectivity even in remote maritime environments.
The MARTAC portfolio also includes the smaller MANTAS T12, which features a unique semi-submersible capability. Through its “gator mode” awash deck feature, the MANTAS can operate with most of the vessel beneath the waves, similar to narco-submarine designs. This platform measures 3.6 meters in length and can support payloads up to 64 kilograms, with missions including surveillance, swarming operations, and electronic warfare.
U.S. Support for Philippine Maritime Capabilities
The presence of MARTAC systems at Balikatan 2025 reflects both U.S. and Philippine investments in unmanned maritime capabilities. The United States has provided the Philippine Navy with four T12 MANTAS and one Devil Ray T38 through foreign military financing as part of a broader effort to strengthen Philippine maritime domain awareness in the South China Sea.6
U.S. Secretary of Defense Lloyd Austin unveiled these transfers during a visit to Palawan in November 2024, alongside Philippine Secretary of National Defense Gilberto Teodoro. “The T12 is a key capability used by Philippine forces to protect its sovereignty and operate throughout its exclusive economic zone in the South China Sea,” the Pentagon stated.7
The Philippine Navy has established Unmanned Surface Vessel Unit One to operate these systems. Former Flag Officer-in-Command Vice Admiral Toribio Adaci explained the strategic rationale: “We have to have USV units for ISR [Intelligence, Surveillance, and Reconnaissance] purposes so that we can improve our capability for maritime domain awareness. That’s how modern navies now evolve, using unmanned systems to complement manned systems.”8
Maritime Security Consortium and Its Regional Impact
The deployment of USVs during Balikatan 2025 occurred within the context of the Pentagon’s new Maritime Security Consortium, a private-public initiative unveiled in November 2024. According to Pentagon officials, $95 million worth of maritime security capabilities were scheduled for delivery to countries across Southeast Asia, with key demonstrations planned during Balikatan 2025.9
U.S. Defense Secretary Pete Hegseth, during his first visit to an Indo-Pacific partner in March 2025, pledged to deploy unmanned surface vehicles for the exercise. A readout of his joint statement with Philippine Defense Secretary Gilberto Teodoro indicated that training on unmanned anti-ship launchers and vessels would “increase the interoperability and operational readiness of U.S. and Philippine forces to leverage cutting-edge military capabilities in Indo-Pacific operational environments.”10
Unlike traditional platforms, USVs can be deployed with minimal infrastructure and personnel signature, making them difficult to detect and track. The semi-submersible capabilities of systems like the MANTAS T-12 further complicate adversary surveillance efforts.
Strategic Implications and Future Direction
The integration of advanced USV capabilities with the 3rd MLR’s littoral regiment concept represents a significant evolution in U.S. military presence and capabilities in the Indo-Pacific. The combination of precision anti-ship missiles, unmanned surface vessels, and expeditionary air defense systems provides a flexible, distributed capability that aligns with the operational challenges of the first island chain.11
Colonel John G. Lehane, Commanding Officer of the 3rd Marine Littoral Regiment, highlighted the synergistic effects of these capabilities: “When employed in conjunction with the Navy-Marine Expeditionary Ship Interdiction System (NMESIS), the MADIS enables 3rd MLR’s ability to conduct maritime strike by giving the Medium-range Missile Battery time to emplace, fire the NMESIS, and displace without fear of being targeted by drones and small unmanned aerial systems.”12
The focus on the Batanes Islands and Luzon Strait during Balikatan 2025 underscores the strategic geography at play. These locations sit astride potential conflict zones and critical sea lanes, making them essential to any maritime security architecture in the region. Philippine Army Brigadier General Mike Logico, the Exercise Balikatan spokesperson, emphasized this point: “Every country big or small has an absolute and inalienable right to defend itself. Maritime Key Terrain Security Operations training increases our combined ability to secure and defend our territories.”13
Conclusion
The 3rd Marine Littoral Regiment’s Littoral Rotational Force-Luzon provides a persistent, forward-deployed presence optimized for distributed operations in littoral environments. The integration of MARTAC USVs adds a new dimension to maritime domain awareness and potential strike operations, while maintaining operational flexibility and reduced signature.
The exercise also highlighted the deepening U.S.-Philippine defense partnership, with both nations investing in complementary capabilities and operational concepts. As tensions persist in the South China Sea and broader Indo-Pacific region, the combination of advanced technology, innovative organizational structures, and allied cooperation demonstrated at Balikatan 2025 provides a template for future security cooperation in this critical theater.
1. https://www.marines.mil/News/News-Display/Article/4156181/philippine-us-troops-kick-off-exercise-balikatan-2025/; https://news.usni.org/2025/03/27/marine-corps-to-debut-new-philippine-rotational-force-at-balikatan-2025-drills
4. https://www.imef.marines.mil/Media-Room/Press-Releases/Announcement/Article/4168249/us-marine-corps-joint-force-deploy-nmesis-to-batanes-for-exercise-balikatan-2025/; https://www.perplexity.ai/search/could-you-source-this-lt-gen-m-jBqluAWwQJK5Ud0JuLq1Tw
5. https://www.navalnews.com/naval-news/2025/05/u-s-special-forces-train-with-usvs-in-the-philippines/
10. https://ipdefenseforum.com/2025/04/u-s-deploying-advanced-capabilities-concepts-to-philippines-for-balikatan-2025/; https://news.usni.org/2025/03/28/secdef-hegseth-announces-marine-anti-ship-missile-deployment-to-balikatan-defense-industrial-base-cooperation-with-manila-in-philippines-visit
12. https://www.3rdmlr.marines.mil/Media-Room/Stories/Article/Article/4162977/enhanced-defense-3d-mlr-deploys-madis-to-philippines-for-balikatan-2025/; https://theaviationist.com/2025/04/24/usmc-madis-nmesis-deployed-balikatan-2025/
13. https://ipdefenseforum.com/2025/10/balikatan-2025-builds-philippine-resilience-multinational-military-capacity/; https://news.usni.org/2025/08/29/philippine-military-opens-new-luzon-strait-base-near-taiwan