Pakistan Addresses Indian Submarine Threats by Conducting Comprehensive Coastal War Exercises

The Pakistan Navy has initiated an extensive two-day maritime exercise throughout its coastal and port facilities, enhancing its defensive stance against sub-conventional and asymmetric maritime threats—an urgency heightened by a history of Indian submarines persistently trying to infiltrate Pakistan’s territorial waters.

Taking place from June 1 to 2, 2025, the exercise occurred amid a tense military standoff between the nuclear-capable neighbors, following four days of continuous cross-border conflicts that included precision airstrikes, ballistic missile launches, armed drone incursions, and ongoing artillery exchanges along the Line of Control.

As stated by Commodore Ahmed Hussain, the Director General Public Relations for the Pakistan Navy, the exercise was meticulously crafted to “validate and refine tactics, techniques and procedures (TTPs) to ensure a strong defense of critical maritime infrastructure against evolving asymmetric threats.” The Navy emphasized that “the exercise involved coordinated operations by PN (Pakistan Navy) Fleet units, Pak Marines, SSG (Navy), and Naval Aviation assets,” showcasing the integration of operations across various domains to tackle the growing challenges of unconventional warfare.

Simulated threats encompassed infiltration by enemy special forces, underwater sabotage, drone swarm attacks, and coordinated multi-domain assaults—scenarios that are directly pertinent to the current Indian naval doctrine, which focuses on network-centric warfare and maritime coercion. These drills were conducted just 48 hours after Indian Defence Minister Rajnath Singh issued a stern warning that India would not hesitate to utilize its naval capabilities in response to “any future aggression by Pakistan,” a remark widely interpreted as a signal of increasing naval assertiveness in the Indian Ocean Region (IOR).

In response, Pakistan’s military reaffirmed its strong dedication to protecting its sovereignty and territorial integrity, referencing a previous statement from May 12 that cautioned about a “comprehensive and decisive” reaction to any infringement of its maritime boundaries.

PN conducted 2-day Ex focusing on countering sub-conventional & asymmetric threats across all major ports & harbours of Pak, aimed at validating & refining Tactics, Techniques & Procedures to ensure robust defence of critical maritime infrastructure against asymmetric threats.1/3 pic.twitter.com/R1IsajwyBB

— DGPR (Navy) (@dgprPaknavy) June 1, 2025

Rear Admiral Faisal Amin, Commander Coast (COMCOAST), personally inspected various operational stations during the exercise and witnessed live-action simulations, which included port breach responses and underwater threat interception drills carried out by the Navy’s Special Services Group and anti-sabotage teams.

In his comments, Rear Admiral Amin commended the readiness and professionalism exhibited by the deployed forces and stressed that safeguarding port infrastructure—such as Gwadar and Karachi—is not merely a security issue, but a cornerstone of Pakistan’s economic resilience and the stability of its energy corridor under CPEC. “The Pakistan Navy is dedicated to maintaining a high level of readiness to address all types of threats and is continuously enhancing its ability to defend maritime frontiers against emerging challenges,” Commodore Hussain concluded.

This commitment is not just rhetorical—Pakistan has a longstanding history of intercepting Indian undersea assets attempting covert incursions into its territorial waters, with the most recent incident confirmed during Exercise SEASPARK-22 in March 2022. In that 2022 event, a Pakistan Navy anti-submarine warfare (ASW) unit successfully detected and tracked an Indian Kalvari-class diesel-electric submarine, which had tried to penetrate Pakistan’s maritime zone under the guise of war games and electronic silence.

The Indian submarine, operating at snorkel depth to recharge its lithium-ion batteries, was identified by Pakistan’s comprehensive maritime domain awareness network, which is believed to include P-3C Orion aircraft, towed sonar arrays, and seabed hydrophone sensors.

“Nevertheless, once again, through unwavering vigilance and professionalism, the Pakistan Navy has successfully thwarted an attempt by an Indian submarine to enter Pakistani waters,” stated the ISPR, highlighting that a comprehensive monitoring protocol was in effect. The statement further noted, “A strict monitoring watch and rigorous vigilance procedures were implemented. Consequently, the Pakistan Navy’s Anti-submarine warfare unit took the initiative and intercepted and tracked the latest Indian submarine, Kalvari, ahead of time.”

This incident in 2022 marked the fourth confirmed interception of an Indian submarine by Pakistan since 2016, following previous attempts in October 2019 and November 2016, which were also repelled by long-range maritime patrol assets and coastal sonar networks.

The Kalvari-class submarines are diesel-electric attack submarines derived from the French Scorpène-class design, built in India under Project-75. These submarines boast advanced stealth capabilities, including acoustic silencing techniques and low radiated noise levels, making them challenging to detect. They are equipped with heavyweight torpedoes and SM.39 Exocet anti-ship missiles, which enhance their offensive capabilities.

Additionally, the submarines incorporate the SUBTICS combat management system, which integrates all onboard sensors and weaponry for effective operation. The recurring incidents of underwater surveillance attempts indicate that a broader undersea shadow war is developing between India and Pakistan, with ramifications that extend beyond regional rivalry and impact global maritime stability in the Western Indian Ocean and Hormuz approaches.

Naval analysts emphasize that as both countries continue to expand their submarine fleets—India through future Project-75(I) SSNs and Arihant-class SSBNs, and Pakistan through its acquisition of eight Chinese Type 039B Hangor-class SSKs—submerged confrontations are expected to increase in both frequency and complexity.

These changing dynamics highlight the growing necessity for strong command-and-control systems, strategic restraint, and open military-to-military communication channels to prevent unintended escalation in the maritime sphere, where transparency is fundamentally restricted.

As Pakistan indicates its intention to fortify its coastline and vital sea routes against grey-zone activities, the recent military exercises and incidents involving Indian submarines serve as a clear reminder that South Asia’s most perilous flashpoint may now be submerged beneath the surface.

India’s submarine fleet acts as the silent spearhead of the country’s maritime deterrence strategy, integrating legacy Soviet vessels, contemporary French-origin diesel-electric submarines, and a developing yet formidable indigenous nuclear submarine capability. With a combination of conventional and nuclear-powered assets, the Indian Navy’s submarine fleet is designed to execute multi-domain operations that range from sea denial and anti-surface warfare to second-strike nuclear deterrence and ISR (intelligence, surveillance, reconnaissance) missions throughout the Indian Ocean Region (IOR).

As of mid-2025, the Indian Navy operates a fleet of 17 submarines—consisting of 15 diesel-electric attack submarines (SSKs) and two nuclear-powered vessels—establishing itself as a powerful undersea force in the Indian Ocean Region.

At the forefront of India’s traditional undersea capabilities are six Kalvari-class submarines, which are based on the French Scorpène design and constructed domestically under Project-75. Five vessels—INS Kalvari, Khanderi, Karanj, Vela, and Vagir—are currently operational, while the sixth, INS Vagsheer, is in the process of sea trials and is expected to be commissioned by the end of 2025.

Equipped with Exocet anti-ship missiles and heavyweight torpedoes, the later Kalvari units are anticipated to feature air-independent propulsion (AIP), which will greatly improve their endurance and stealth in littoral combat zones. Additionally, India operates eight upgraded Kilo-class submarines, referred to locally as the Sindhughosh-class, which were acquired from Russia between the late 1980s and early 2000s. Despite their age, ongoing mid-life refits and the integration of Club-S cruise missiles have maintained their effectiveness in strike and patrol missions.

Complementing these submarines are four German-made Type 209/1500 submarines, known as the Shishumar-class, which are primarily utilized for training and coastal defense, with one unit recently undergoing life-extension upgrades. India’s nuclear deterrent at sea is represented by the Arihant-class SSBNs, which constitute the maritime component of its strategic triad.

INS Arihant, which has been operational since 2016, is equipped with K-15 SLBMs (with a range of 750 km), while her successor, INS Arighat, is in the final stages of outfitting and is expected to carry K-4 SLBMs with an extended range of up to 3,500 km.

Regarding nuclear attack capabilities, India once operated the INS Chakra II, a leased Akula-class SSN from Russia, which was returned in 2021. Currently, there are plans to lease another Akula-class submarine (Chakra III), while India is also developing six indigenous SSNs as part of a Strategic Forces Command initiative, designed to be the core hunter-killer component of its future undersea fleet.

The next significant advancement for India—Project-75I—aims to procure six advanced SSKs equipped with AIP and vertical launch systems for BrahMos-class cruise missiles, although there are ongoing procurement delays. The contenders for this project include platforms from South Korea, Russia, Germany, and Spain, with a final decision anticipated between 2025 and 2026. Although India’s submarine fleet lags behind China in terms of numbers, it benefits from improved network integration, long-range maritime patrol aircraft (P-8I Poseidon), and an increasing capacity for indigenous production.

Concurrently, as geopolitical competition escalates in the Indian Ocean Region (IOR), Pakistan is reinforcing its undersea warfare capabilities by modernizing its submarine fleet—quietly yet decisively strengthening its sea-denial strategy and nuclear second-strike deterrent. Central to Pakistan’s undersea warfare strategy is a combination of legacy platforms designed in France and a new generation of modern Chinese submarines—together forming a credible, multi-layered force capable of surveillance, interdiction, and strategic deterrence across critical maritime chokepoints.

At present, the Pakistan Navy has five active diesel-electric attack submarines (SSKs): three upgraded Agosta-90B (Khalid-class) submarines equipped with Air Independent Propulsion (AIP) systems, and two older Agosta-70 (Hashmat-class) submarines, which mainly serve in training and support functions. The Agosta-90B class, which includes PNS Khalid, PNS Saad, and PNS Hamza, constitutes the backbone of Pakistan’s submarine fleet. These vessels, with a submerged displacement of approximately 2,000 tonnes, were built with French collaboration in the late 1990s and early 2000s and are equipped with MESMA AIP modules, greatly enhancing their underwater endurance compared to conventional diesel-electric models.

All three submarines have received significant mid-life upgrades as part of a $350 million agreement with Turkey’s STM (Savunma Teknolojileri Mühendislik), incorporating advanced sonar systems, combat management systems, electronic warfare enhancements, new periscopes, and fire-control systems that are compatible with heavyweight torpedoes and submarine-launched cruise missiles.

On the other hand, the Agosta-70 class, which includes PNS Hashmat and PNS Hurmat, was commissioned in the late 1970s and continues to operate, reportedly being utilized for secondary operational roles and training purposes. Nevertheless, the focal point of Pakistan’s submarine modernization initiative is the upcoming introduction of eight Hangor-class submarines, based on the Chinese Type 039B (Yuan-class) design—a stealth-optimized, AIP-equipped platform anticipated to transform the regional underwater balance.

Under a 2015 agreement between Islamabad and Beijing, valued at around $4–5 billion, four submarines are being constructed in China, while the other four are being built at Karachi Shipyard & Engineering Works (KSEW) as part of a technology transfer arrangement. By 2025, the first two submarines—PNS Hangor and PNS Shushuk—have already been launched at Chinese shipyards, with deliveries expected by late 2025 and 2026, respectively.

These Hangor-class submarines, with a displacement of around 2,800 tonnes, are said to be designed to carry the Babur-3 submarine-launched cruise missile (SLCM)—a nuclear-capable system boasting an estimated range of 450 km, which provides Pakistan with a credible second-strike capability from underwater platforms.

Fitted with sophisticated passive/active sonar systems, integrated combat systems, and long-endurance AIP modules, the Hangor-class will enable the Pakistan Navy to sustain a continuous undersea presence throughout the Arabian Sea and into the Strait of Hormuz.

This new generation of submarines will greatly enhance Pakistan’s capacity to execute area denial operations, strategic ISR, and deterrent patrols deep within contested maritime regions—especially in reaction to Indian Navy deployments and joint exercises with QUAD nations.

Simultaneously, Pakistan is advancing its anti-submarine warfare (ASW) capabilities through the use of P-3C Orion maritime patrol aircraft, unmanned undersea sensors, and an expanding network of surface combatants to safeguard its own fleet and counter enemy incursions—particularly in light of repeated incidents of Indian submarine detection in 2016, 2019, and most recently in 2022.

The leadership of Pakistan’s navy has consistently emphasized the strategic importance of submarines in protecting vital sea lanes and deterring hostile naval activities near Gwadar Port, which is a crucial component of the China-Pakistan Economic Corridor (CPEC).

Considering the swift modernization of the Indian Navy’s own undersea capabilities—including Kalvari-class (Scorpène) submarines and a growing nuclear fleet—Pakistan’s focus on indigenous construction, AIP technology, and the integration of strategic weapons signifies a purposeful transition towards enhanced survivability, autonomy, and technological equivalence.

By the end of the decade, the Pakistan Navy is anticipated to operate at least 11 modern submarines, the majority of which will be AIP-capable, positioning it as one of the most formidable undersea forces in the region, particularly when compared to its relative size and conventional capabilities.