Acquiring Submarines to Enhance Maritime Deterrence against Security Challenges in the West Philippine Sea
- museomaritimo
- 12 hours ago
- 5 min read
April 16, 2026 – Pasig City, NCR, Philippines
An article by SM Floralde
The main objective of the Philippine Navy (PN) is to defend the nation’s territory. This naval warfare service branch of the Armed Forces of the Philippines secures the Philippine waters against threats like piracy and trafficking. At the same time, it supports disaster relief, enforces maritime laws, and aids in national development. And in order for the navy to do its duties and responsibilities, it needs a fleet that is capable of defending our country against all foreign and domestic challenges.
In recent years, the Philippine Navy has been undergoing modernization. It is shifting from internal security to territorial defense, which leads to adding more capable, modern ships to its fleet. But as of the moment, the Navy operates a mix of modern and aging vessels for maritime defense, primarily a couple of frigates and corvettes. The fleet also includes a number of landing platform docks, amphibious ships, and smaller patrol crafts. However, compared with the armed forces of other countries with impressive fleets, we have yet to acquire underwater vessels called submarines.
After all these years, why has the Philippine government not been able to acquire one?
The Philippines currently has no submarines because historically, the AFP is given limited defense budgets. For practical needs, the government has prioritized surface ships over underwater capabilities.
Considering its total operational expenses, a submarine program is estimated at ₱80 billion to ₱110 billion. Moreover, the high cost of training, maintenance, and necessary infrastructure are other reasons why they have not acquired this extremely expensive vessel. While part of the long-term AFP modernization plan, its acquisition has been delayed, with planners now focusing on the 2025–2028 timeframe.
Submarine—Definition and History
Based on the definition found in Britannica.com, a submarine is a specialized naval vessel “that is capable of propelling itself beneath the water as well as on the water’s surface.” It is designed to operate independently for extended periods. Utilizing ballast tanks for buoyancy control and high-strength steel hulls to withstand deep-sea pressure, they are primarily used for military patrolling, intelligence gathering, and scientific research. These large, self-contained vessels, used mainly by navies, are often referred to as "boats" and can be diesel-electric or nuclear-powered, allowing for long-duration, deep-sea operation. Moreover, submarines are usually built for warfare and armed with torpedoes or guided missiles.
According to maritime history, submarines were first used during the first World War. They became “a major factor in naval warfare during World War I (1914–18), when Germany employed them to destroy surface merchant vessels. In such attacks submarines used their primary weapon, a self-propelled underwater missile known as a torpedo.” With their significant impact in naval warfare, “submarines played a similar role on a larger scale in World War II (1939–45), in both the Atlantic (by Germany) and the Pacific (by the United States).”
After the two world wars, the superpower nations continued the development of their submarine capabilities. So, “In the 1960s the nuclear-powered submarine, capable of remaining underwater for months at a time and of firing long-range nuclear missiles without surfacing, became an important strategic weapon platform. Armed with torpedoes as well as antiship and antisubmarine missiles, the nuclear attack submarine has also become a key element of naval warfare."
Current Status of the Philippine Acquisition of Submarines
NavalNews.com reported, "The Philippines remains among the few countries in the region without a submarine fleet, a gap that underscores the urgency of its modernization drive." In order to boost the country’s maritime security, the Philippines moves with its plans to acquire submarines. In fact, the planning stage has already started. Just last year, no less than President Marcos Jr. met with a giant shipbuilder from South Korea who offered support to the Philippine Navy’s submarine program.
According to Philstar.com, Hanwha Ocean discussed its proposal, which involves “the building of a submarine base, the establishment of a local maintenance, repair and overhaul center and the training of Filipino naval operators, maintainers and commanders using advanced simulators and systems." The Presidential Communications Office added that “executives of the Hanwha Ocean informed the President of their plans for the deployment of KSS-III PN (Philippine Navy) submarines equipped with modern sonar and combat systems and lithium-ion batteries for longer underwater endurance, along with technology transfer and partnerships with local industries to advance the Philippines’ self-reliant defense capability.” In line with this proposal and as part of modernization plans, "the AFP aims to purchase at least two submarines of the diesel-electric type. The budget for the acquisition of submarines ranges from P80 billion to P110 billion."
Furthermore, other foreign investors showed interest in supporting the country’s submarine program. Aside from that of South Korea, global defense contractors from France, Spain, Italy, and Germany are leading candidates for building the submarines, with discussions highlighting technology transfer and domestic maintenance.
While the government is still finalizing its acquisition plans, the government is implementing an interim strategy against underwater challenges. In the absence of submarines, the Philippine Navy is focusing on strengthening its anti-submarine warfare (ASW) capabilities and using maritime surveillance to manage existing threats. In line with this strategy, the acquisition of Leonardo AW-159 Wildcat helicopters and modern frigates like the BRP Miguel Malvar and Jose Rizal classes is implemented to focus on detection and tracking to enhance maritime security.
Future Outlook on Submarine Capabilities
The Philippines plans to acquire diesel-electric submarines under the Armed Forces of the Philippines (AFP) Horizon 3 (or Re-Horizon 3) of its military modernization program, aimed at patrolling the depths and deterring aggressive actions in the West Philippine Sea. Aside from the two diesel-electric-powered submarines, the AFP has confirmed that Re-Horizon 3 will also involve “more than 12 MRF aircraft (likely the F-16 C/D Block 70/72), an additional 12 FA-50 Fighting Eagle aircraft, two more corvettes or frigates, offshore patrol vessels, fast attack boats, S-70 Black Hawk helicopters, more air defence, surface/sub-surface and missile systems, and cyber systems."
As the country is aiming to procure its first-ever submarines, the acquisition represents a shift in Philippine naval doctrine from a surface-focused fleet to a multi-domain force, utilizing modern diesel-electric technology to counter regional security challenges. Therefore, it is high time for this Southeast Asian country to move forward in improving its defense capabilities in the 21st century.
With the growing tensions in the West Philippine Sea, the Armed Forces of the Philippines Chief of Staff Gen. Romeo Brawner Jr. expressed the urgent need for a submarine program. He clearly pointed out, “We are an archipelago, so we need this kind of capability because it’s really difficult to defend the entire archipelago without submarines.”
References:
1. Aaron-Matthew Lariosa (2025, February 13). Philippines to Procure Submarines for Archipelagic Defense. NavalNews.com.
2. Norman C. Polmar. Britannica Editors (2026, Apr. 14). Britannica.com.
3. Alexis Romero - The Philippine Star (2025, November 2). Philippines closer to acquiring submarine for maritime security. Philstar.com
4. Frances Mangosing (2025, March 11). Hanwha Ocean presents KSS-III PN submarine offer to Philippines’ President Marcos. NavalNews.com.
5. Priam Nepomuceno (2025, January 23). PH's Offshore Combat Force equipped with anti-submarine capabilities. PNA.gov.ph.
6. Haena Jo (2025, June 23). Philippines military modernisation: revamped but not resolved. IISS.org.
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