Pakistan Navy’s Shallow Water Attack Submarine (SWATS): The Road to an Original Design

Why It Matters

Securing a SWATS fleet will give Pakistan credible shallow‑water strike and surveillance capability while jump‑starting domestic submarine design expertise essential for future medium‑displacement and strategic submarines.

Key Takeaways

• Pakistan plans at least three 700‑ton SWATS boats for littoral ops
• Turkey's STM500, 49 m, 700 t, 18 kt speed, 30‑day endurance, in testing
• STM500 can launch eight heavyweight torpedoes and anti‑ship missiles
• SWATS serves as design bridge to Pakistan’s first indigenous submarine
• Chinese CSOC MS200 offers a smaller, lower‑cost alternative

Pulse Analysis

Pakistan’s current submarine force relies on the 2,800‑ton Hangor‑class, a Chinese‑derived AIP platform optimized for blue‑water patrols. While the Hangor expands Pakistan’s anti‑access/area‑denial (A2/AD) reach, its size and draft limit effectiveness in the shallow, cluttered waters of the Makran coast, Karachi and Gwadar. The aging Italian‑built MG110 midget subs, which have served the Special Service Group since the early 1990s, are nearing retirement, leaving a capability gap for coastal surveillance, mine‑countermeasure support, and special‑operations insertion. A dedicated shallow‑water attack submarine would address these gaps, offering both conventional anti‑ship firepower and the endurance needed for prolonged littoral missions.

Turkey’s Savunma Teknolojileri Mühendislik (STM) has positioned its STM500 as the frontrunner for the SWATS contract. The 49‑metre, 700‑ton vessel boasts a top speed above 18 knots, a 30‑day deployment window for a crew of 22 plus eight special‑operations personnel, and a weapons suite that includes four torpedo tubes capable of firing eight heavyweight torpedoes and the AKYA‑guided anti‑ship missile. Diesel‑electric propulsion paired with lithium‑ion batteries—and optional Stirling AIP—offers low acoustic signatures crucial for shallow‑water stealth. Pressure‑hull testing concluded in 2024, and the design was showcased at SAHA EXPO, underscoring STM’s readiness. China’s MS200 mini‑sub presents a lower‑cost alternative, but STM’s existing contracts for the Agosta‑90B upgrade, Babur‑class corvettes, and the PNS Moawin tanker give it a deeper foothold in Pakistan’s defence supply chain.

Beyond the immediate operational benefits, the SWATS program is a strategic industrial catalyst. By co‑developing the STM500 with KSEW and the Maritime Technologies Complex, Pakistan can acquire hands‑on experience in hull design, systems integration, and autonomous underwater vehicle deployment—skills absent from its current license‑build arrangements. Mastery of these competencies paves the way for a larger, 1,500‑2,000‑ton indigenous submarine that could replace the aging Agosta‑90B fleet by the 2040s and eventually host vertical launch systems for Babur‑series cruise missiles. The contract’s structure—whether a straight build‑to‑print purchase or a joint development—will signal Pakistan’s commitment to evolving from a submarine‑assembler to a submarine‑designer, a transformation critical for long‑term maritime deterrence and regional power projection.