Turkey Commissions TCG Hızırreis: Second Reis-Class AIP Submarine Transforms Ankara’s Naval Power

(DEFENCE SECURITY ASIA) — Turkey has entered a decisive new phase in its naval transformation with the commissioning of the TCG Hızırreis (S-331), the second submarine in the highly advanced Reis-class fleet that forms the backbone of Ankara’s next-generation underwater warfare capability.

The handover ceremony on November 27, 2025, at Gölcük Naval Shipyard marks a watershed moment in Turkey’s long-term maritime defence strategy during a period of accelerating geopolitical tensions across the Eastern Mediterranean and Black Sea.

The induction of TCG Hızırreis represents more than a fleet expansion, because it signals a deliberate strengthening of Turkey’s A2/AD (anti-access/area-denial) posture in waters increasingly shaped by energy disputes, great-power competition, and contested exclusive economic zones.

The commissioning underscores Turkey’s growing confidence in its evolving defence industrial ecosystem, because the submarine was delivered jointly by Germany’s ThyssenKrupp Marine Systems (TKMS) and the indigenous Gölcük Naval Shipyard—an arrangement that has progressively shifted technological expertise and integration capabilities into Turkish hands.

The arrival of TCG Hızırreis comes just over a year after the induction of the lead vessel, TCG Piri Reis (S-330), which entered service on August 24, 2024 during a high-profile ceremony attended by President Recep Tayyip Erdoğan, reinforcing the strategic importance Ankara places on undersea warfare.

With two air-independent propulsion (AIP) submarines now in operational service, Turkey gains a powerful asymmetric advantage, because these platforms can execute long-endurance covert missions without surfacing, making them extremely difficult for rival forces to detect or counter.

The broader Reis-class program—valued at €2.06 billion, equivalent to approximately USD 2.24 billion and RM 10.17 billion—remains a centrepiece of Turkey’s “Blue Homeland” doctrine, a strategic vision that emphasises maritime sovereignty, sea-lane defence, and resource security across the Aegean, Mediterranean, and Black Sea.

The commissioning of TCG Hızırreis arrives at a moment when Turkey’s undersea fleet is transitioning from legacy diesel-electric boats toward a more survivable, stealth-optimised force capable of shaping regional naval balances for decades.

Evolution of Turkey’s Submarine Force and Historical Military Trajectory

Turkey’s pursuit of advanced submarine capability is rooted in a naval tradition that stretches back to the Ottoman Empire yet reached modern sophistication in the mid-20th century through acquisitions from the United States and Germany.

The Turkish Navy’s backbone for decades has consisted of Type 209/1200 and Type 209/1400 Preveze-class diesel-electric submarines, platforms that have performed reliably but face diminishing relevance as neighbouring navies integrate newer AIP-equipped boats and advanced anti-submarine warfare (ASW) sensors.

The decision to adopt the Reis-class, based on the German Type 214 design, emerged from a 2008 tender that saw TKMS win over competing proposals from France’s DCNS and Spain’s Navantia, with Turkey prioritising proven AIP performance, modularity, and long-term upgrade pathways.

The official launch of the program in 2011 paved the way for major industrial collaboration, beginning with the keel laying of TCG Piri Reis in September 2015, followed by its launch in December 2019 in a ceremony that signalled Turkey’s determination to accelerate its naval modernisation timeline.

Sea trials for TCG Piri Reis commenced in December 2022 and culminated in its 2024 commissioning, during which TCG Hızırreis began parallel trials and TCG Murat Reis (S-332) entered the outfitting phase, demonstrating the production cadence Turkey has now mastered.

The naming convention of the submarines—Piri Reis, Hızırreis, Murat Reis—reflects a national narrative deeply intertwined with the legacies of Ottoman maritime commanders, including the famed admiral and cartographer Piri Reis and the legendary corsair-admiral Hızır Reis, also known as Barbarossa.

The TCG Hızırreis completed its first sea trials in September 2024, including a successful maiden dive that validated its AIP operations, sonar performance, and submerged manoeuvrability, before advancing to full combat readiness in 2025.

This rapid timeline underscores the growing sophistication of Turkey’s defence industry, which has steadily integrated local content through companies such as STM, which contributed to systems integration—including elements of the AIP, combat systems, and sonar architecture.

Turkey’s indigenisation strategy has been strongly aligned with President Erdoğan’s national defence vision, a policy that helped propel Turkish defence exports to exceed USD 6.3 billion (approximately RM 28.62 billion) in 2024.

The integration of Turkish-developed technologies into German-origin platforms also reflects an intentional diversification away from dependency on foreign suppliers and towards a hybrid industrial model that strengthens Turkey’s autonomy in critical naval capabilities.

Advanced Technical Capabilities of the Reis-Class Submarines

The Reis-class submarines, designated Type 214TN in Turkish service, embody advanced underwater engineering built around stealth, endurance, and multi-domain lethality.

Each submarine measures 68 metres in length with a submerged displacement exceeding 2,000 tonnes and carries a complement of 40 personnel, creating a highly efficient crew structure suitable for prolonged operations in contested environments.

The defining feature of the class is its hydrogen fuel-cell-based AIP system, which enables the submarine to remain submerged for up to three weeks—dramatically extending its ability to evade detection and conduct covert surveillance or strike missions.

The propulsion system integrates a Siemens Permasyn electric motor for ultra-silent operations, paired with MTU diesel engines that provide surface transit capability, allowing the submarine to achieve speeds of more than 20 knots while submerged and around 12 knots on the surface.

The hydrodynamic hull is coated with advanced acoustic dampening materials that reduce noise propagation, significantly complicating detection by active and passive sonar systems used by regional rivals.

The armament suite includes eight 533mm torpedo tubes capable of deploying heavyweight torpedoes such as the German DM2A4 Seehecht and the indigenous Turkish Akya, a new-generation torpedo that underscores Turkey’s expanding underwater munitions ecosystem.

The submarine can also launch Sub-Harpoon anti-ship missiles or Turkey’s domestically developed Atmaca submarine-launched variant once integration is completed, further enhancing Ankara’s maritime strike portfolio.

Beyond anti-ship warfare, the Reis-class can deploy naval mines and—as Turkey develops long-range cruise missile integration—may eventually support limited land-attack operations, expanding its role into strategic deterrence and deep-strike missions.

The sensor suite incorporates advanced periscopes manufactured by Aselsan, high-resolution passive and active sonar arrays from Atlas Elektronik, and electronic warfare systems capable of detecting, classifying, and jamming hostile emitters.

Havelsan’s locally integrated combat management system offers real-time data fusion, enabling seamless coordination with unmanned surface vessels (USVs), unmanned underwater vehicles (UUVs), and network-centred naval formations, an increasingly important element of Turkey’s naval doctrine.

Compared with regional peers such as Greece’s Type 214 Papanikolis-class or Israel’s Dolphin-class submarines, the Type 214TN fielded by Turkey features higher levels of modularity, indigenous technology integration, and future-proofing for vertical launch system (VLS) upgrades, potentially enabling future ballistic-missile capabilities.

The combination of endurance, stealth, and multi-domain lethality positions the Reis-class as a formidable underwater force multiplier within Turkey’s strategic environment.

Strategic and Geopolitical Impact in the Eastern Mediterranean and Black Sea

The entry of TCG Hızırreis into service comes at a moment of acute maritime friction in the Eastern Mediterranean, where competing energy exploration activities and overlapping EEZ claims have driven confrontations between Turkey, Greece, and Cyprus.

Turkey’s ability to deploy AIP-equipped submarines for months-long rotations enables it to maintain persistent underwater surveillance and deterrence patrols across contested waters, complicating Greek and EU naval planning.

During the 2020 Oruç Reis seismic survey standoff, Turkey recognised the necessity of maintaining a stealthy undersea presence to secure hydrocarbon exploration vessels and disrupt potential adversary blockades, a lesson reflected in its accelerated submarine procurement.

In the Black Sea, Russia’s ongoing war in Ukraine has transformed the region into one of the world’s most heavily monitored maritime theatres, with Turkish submarines playing a crucial role in intelligence collection and sea-denial operations.

Turkey’s control of the Bosporus and Dardanelles under the Montreux Convention already grants it decisive geopolitical leverage, and the addition of AIP submarines enhances its ability to monitor Russian naval movements without escalating into direct confrontation.

Admiral Ercüment Tatlıoğlu stated that the Reis-class contributes to “long-term submarine deterrence capability,” a declaration that highlights the submarines’ role in reinforcing Turkey’s long-range strategic influence.

Turkey’s expanding naval power also complements its growing defence exports, including MILGEM-class corvettes supplied to Pakistan and T129 ATAK helicopters operated by the Philippines, reinforcing Ankara’s emergence as a global arms supplier.

With the Reis-class serving as proof of Turkey’s advanced undersea engineering, Ankara is now poised to explore future export variants, potentially offering lower-cost alternatives to Type 214 or KSS-III submarines in the Asian and African defence markets.

This export positioning places Turkey in competition with established submarine suppliers such as Germany, South Korea, France, and China, signalling Ankara’s ambition to become a top-tier naval technology provider.

Turkey’s Defence Industrial Trajectory and Future Naval Ambitions

The Reis-class is not intended as an endpoint but a stepping stone toward full autonomy in submarine design and production through the MILDEN (Milli Denizaltı) National Submarine program.

Construction of MILDEN officially began on January 2, 2025, with Turkey aiming to field fully indigenous AIP submarines by the early 2030s, incorporating next-generation propulsion systems such as lithium-ion batteries or hybrid-nuclear configurations.

Admiral Tatlıoğlu has openly stated Turkey’s ambition to acquire nuclear-powered submarines, a capability that would elevate the Turkish Navy into an elite global category alongside France, the United Kingdom, and China.

The rapid growth of Turkey’s defence industrial base—now producing 70–80% of its military hardware domestically—is driven by firms such as Roketsan, Aselsan, STM, Havelsan, and Baykar, all of which have become cornerstones of Turkey’s maritime and aerospace modernisation.

The integration of UAVs such as the Bayraktar TB3 and Kızılelma UCAV aboard the amphibious assault ship TCG Anadolu signals a pivot toward a hybrid surface-unmanned naval force structure that enhances Turkey’s maritime reach.

Turkey continues to face challenges, including Western sanctions linked to its acquisition of the Russian S-400 system and sporadic supply chain constraints, but Ankara has mitigated vulnerabilities by strengthening partnerships with Asian and Middle Eastern defence markets.

The remaining Reis-class submarines—TCG Murat Reis, TCG Aydın Reis, TCG Seydi Ali Reis, and TCG Selman Reis—are scheduled for delivery through 2029, ensuring a gradual phasing out of older Type 209 submarines and creating a homogeneous AIP-capable fleet.

The expansion of Turkey’s undersea fleet has prompted regional responses, because Greece has accelerated submarine upgrades and frigate acquisitions, while Israel and Egypt continue expanding their naval forces through U.S. and European support.

Environmental, geographical, and operational risks remain ever-present in the shallow and complex Aegean Sea, where submarine manoeuvrability and crew proficiency are critical to avoiding collisions, detection, or navigational hazards.

Turkey’s investment in submarine simulators and its joint exercises with Pakistan in November 2025 demonstrate its commitment to developing a highly trained and strategically flexible undersea force.

TCG Hızırreis and the Rise of a Confident Maritime Power

The commissioning of TCG Hızırreis marks a pivotal turning point in Turkey’s emergence as a confident naval power capable of projecting influence across the Mediterranean, Aegean, and Black Sea.

By blending imported precision engineering with increasingly indigenous technological innovation, Turkey has accelerated its transition from a regional maritime actor into a strategically relevant undersea force.

The Reis-class submarines offer Turkey unprecedented endurance, stealth, and multi-domain lethality, crucial attributes for safeguarding maritime interests while operating in some of the world’s most politically volatile waters.

As the MILDEN program matures and Turkey advances toward nuclear submarine aspirations, Ankara’s naval fleet may evolve from regional deterrent to global strategic instrument.

In an era defined by great-power competition, shifting alliances, and contested maritime geographies, the TCG Hızırreis stands as a powerful symbol of Turkey’s determination to secure its “Blue Homeland” and assert its role as a rising maritime force capable of shaping the security architecture of the wider region.

— DEFENCE SECURITY ASIA