South Korea Moves to Arm the Philippines With Next-Gen KSS-III Attack Submarines.

President Ferdinand Marcos Jr. met with Hanwha Ocean during APEC in Seoul to discuss a complete submarine package for the Philippine Navy, including base construction, MRO, and training. The offer centers on a KSS-III–derived design with lithium-ion batteries, signaling Manila’s most serious undersea modernization push to date.

The Presidential Communications Office announced on November 2, 2025, that President Ferdinand Marcos Jr. met Hanwha Ocean on the sidelines of APEC in South Korea to discuss a turnkey submarine package for the Philippine Navy that pairs new boats with basing, MRO, training and technology transfer. The government readout specifies a plan to build a submarine base, stand up a local maintenance ecosystem, and train operators and commanders on modern simulators, anchored on a KSS III–derived “KSS-III PN” offer with lithium-ion batteries.
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South Korea’s KSS III pairs lithium-ion batteries with AIP for long, quiet patrols and fields six 533 mm tubes plus ten VLS for land-attack and multi-mission operations (Picture source: South Korean MoD).

Hanwha’s proposal rides the momentum of South Korea’s newest diesel-electric design. In the Republic of Korea Navy, the KSS III Batch II stretches to roughly 89.4 meters with a 9.7-meter beam, displacing about 4,000 tons submerged and carrying ten vertical launch cells in addition to six 533 mm tubes. Batch II combines air-independent propulsion with high-capacity lithium-ion batteries, a pairing that lengthens silent endurance and improves sprint-and-drift tactics while cutting maintenance compared with legacy lead-acid banks. Weapons listed for the class include LIG Nex1’s Tiger Shark heavyweight torpedoes, the SSM-700K C-Star family, and vertical launch capability for the Hyunmoo-4-4.

This translates to options the Philippine Navy has never held. Lithium-ion chemistry allows higher sustained submerged speeds between AIP cycles, complicating adversary pattern analysis. A ten-cell VLS is unusual in conventional submarines and brings land-attack and strategic messaging potential, while the tubes support anti-ship, anti-submarine, mine warfare and special operations insertion. In archipelagic chokepoints from the Luzon Strait to the West Philippine Sea, a Li-ion/AIP boat can loiter quietly, relocate quickly, and remain in contact-denied waters for prolonged periods, a marked step up from purely lead-acid SSKs.

Hanwha is not alone in Manila’s submarine race. Naval Group is pushing Scorpene Evolved with a full lithium-ion configuration and its FC2G fuel-cell AIP, now validated by the company’s Indonesia program under a transfer-of-technology model that will build two boats entirely at PT PAL in Surabaya. Spain’s Navantia offers the 3,000-ton S-80 Plus with a third-generation AIP based on bioethanol reforming, a system installed on Spanish hulls and now entering fleet activity. And in April, Italy’s Fincantieri teamed with Germany’s ThyssenKrupp Marine Systems to market the U212 Near Future Submarine to the Philippines, bundling German key technologies and an Italian Navy-backed training concept.

Scorpene Evolved sits in the 2,000-ton class and emphasizes compact architecture, low signatures, and proven localization through partner yards, attractive for a first-time operator building yard skills. S-80 Plus is larger and oceanic, with BEST AIP designed for multi-week submerged endurance and a modern, highly automated platform control system that reduces crewing. U212 NFS is smaller, typically 1,600–1,900 tons surfaced depending on fit, and leans into exquisite acoustic discretion with fuel-cell AIP and lithium-ion batteries now through design milestones, an advantage for navies with lean submariner pipelines. KSS III Batch II is the heavyweight, bringing the only VLS in the field plus a large sensor volume and Li-ion capacity, moving the conversation beyond sea denial to theater-reach strike.

The combat-system layer matters just as much. Hanwha can leverage its Naval Shield pedigree already familiar to the Philippine fleet, and KSS III integrates a modern weapons-handling system from Babcock with South Korean effectors. Scorpene’s CMS is SUBTICS, an integrated suite with a deep export record across four continents. U212 variants use Atlas Elektronik’s ISUS 90, while S-80 combines a Navantia-led combat system developed with Lockheed Martin, giving the Spanish boat an easier path to U.S. and NATO data-link integration. These are not mere brand badges; they define the Philippines’ future sustainment and interoperability graph.

Industry and financing often decide outcomes as much as performance. The submarine program sits inside Re-Horizon 3, a ten-year, roughly 2 trillion peso modernization plan approved in 2024. Philippine officials and multiple public statements have pegged the submarine line at 80 to 110 billion pesos for two boats, basing and logistics. That envelope makes sovereign credits and industrial offsets central to the bid. Naval Group’s Indonesia deal demonstrates heavy localization. Fincantieri and TKMS have signaled a partnership that packages training and key German technologies. Hanwha’s PCO-documented offer to fund basing, MRO and training is designed to lower Manila’s barrier to entry.

Manila has pursued submarines for more than a decade, with earlier evaluations of Scorpene among others, but budget and training realities delayed choices under previous administrations. The Marcos government has moved the requirement into a ten-year frame and is now openly courting multiple vendors, a shift that marks the most serious Philippine submarine push to date. As Armed Forces Chief Gen. Romeo Brawner has argued, defending an archipelago without subs is difficult, a sentiment now paired with funds and state commitments.

South Korea’s broader defense-industrial rise gives its bid political ballast. Seoul has elevated ties with Manila to a strategic partnership, while its defense exports have surged since 2022, with the presidency now targeting a top-four global position by 2030. Reuters reporting this year also chronicles Hanwha Ocean’s global push, including U.S. shipyard moves, and KAI’s fresh sale of 12 FA-50s to the Philippines anchors procurement familiarity between the two countries. Combined, these strands make a Korean submarine path more administratively straightforward for Manila.

In acoustic discretion, the smaller U212 NFS and Scorpene Evolved favor fewer rotating masses and compact machinery spaces that support ultra-low signatures in shallow littorals. In endurance, S-80’s mature AIP concept and KSS III’s Li-ion capacity plus AIP offer the longest submerged persistence windows, useful for covert barrier patrols along the Bashi Channel and northern Palawan passages. In firepower, only KSS III brings an organic VLS for ballistic or land-attack cruise missiles, enabling stand-off strikes and coercive signaling Manila has never owned. Automation levels are converging across the field, but U212 and S-80 advertise leaner crews, a meaningful factor for a navy building a submarine cadre from scratch.

Hanwha Ocean is the rebranded DSME under Hanwha Group control, part of a deliberate consolidation that ties shipbuilding, batteries and electronics into one export engine. That consolidation underwrites delivery schedules and offers Manila an integrated vendor rather than a loose consortium. South Korea’s stated target to climb into the top four defense exporters by the end of the decade, combined with a pattern of local workshare and training pathways across Europe and Asia, sets the context in which the KSS III PN is being pitched.

Hanwha’s concept offers the fastest jump to a high-end undersea deterrent with vertical-launch credibility and a full shore ecosystem from day one. Scorpene Evolved and S-80 Plus lean into transfer of technology and proven AIP pedigrees that de-risk first-fleet operations while fostering local skills. U212 NFS promises a smaller, exceptionally quiet boat with tight manpower demands and a European training backbone. The Philippines wants at least two submarines to start, and this APEC-week engagement has re-set the market in Manila’s favor: multiple competitive offers, credible financing paths, and a realistic ten-year modernization frame.

Written by Evan Lerouvillois, Defense Analyst, Army Recognition Group.

Evan studied International Relations, and quickly specialized in defense and security. He is particularly interested in the influence of the defense sector on global geopolitics, and analyzes how technological innovations in defense, arms export contracts, and military strategies influence the international geopolitical scene.