At the 2025 Combined Naval Event (CNE) in Farnborough, UK — Europe’s largest annual naval gathering — a Greek naval officer presented the Hellenic Navy’s comprehensive submarine modernization plan.
On May 22, 2025, at CNE 2025, a Navy Leaders Conference, Commodore Konstantinos Tourkantonis, Deputy Director of the Armaments Directorate of the Hellenic Navy General Staff, revealed new details for the imminent modernization of the Hellenic Navy’s submarine fleet. It is worth noting that the Greek Commodore previously served as Director of the submarine program, giving him direct and extensive involvement in Greece’s submarine initiatives. He also held the position of Commander of the Hellenic Navy Submarine Command.
Naval News was present for the briefing, titled “Submarine Modernization Across the Hellenic Naval Force,” and here are the key takeaways from the presentation. Note that Greece is planning to construct, at least in part domestically, four (4) new submarines to replace its aging fleet of 50-year-old Type 209 submarines. Some of the candidate designs currently under consideration include the Scorpène and Barracuda from Naval Group, the Type 218 and Type 209NG from TKMS, and the A26 from Saab.
Current Status and Future Intentions
The current submarine force of the Hellenic Navy consists of four Papanikolis-class (Type 214/1600) submarines, one Okeanos-class (Type 209/1500 MLU-AIP), three Poseidon-class (Type 209/1200), and one Glafkos-class (Type 209/1100 MLU) submarine.
The Navy aims to maintain and enhance the operational readiness of its submarine fleet while strengthening its capabilities in the underwater domain. This will be achieved through a mid-life upgrade (MLU) of the existing Type 214 submarines, the replacement of remaining Type 209 vessels with new-generation submarines, and the exploration of advanced technologies for future underwater warfare.
New Submarine Program – Requirements
Regarding the new submarine class, its primary objective is to enable the enforcement of national will through Anti-Access/Area Denial (A2/AD) operations, project force both at sea and ashore, and sustain prolonged missions under constant enemy threat.
The Commodore then outlined a set of general requirements and desired capabilities for the future submarine. These include significantly reduced signatures—specifically, minimized active target strength across all frequency bands, including low-frequency active sonar, as well as reduced acoustic and magnetic signatures. A low indiscretion rate is also essential, with air-independent propulsion (AIP) deemed mandatory. The integration of lithium-ion batteries is also considered a critical feature.
The platform should feature a high degree of automation, with built-in redundancies at both the software and hardware levels, optimized for prolonged ultra-quiet operations. It must also be fully configurable to meet the specific operational requirements of the Hellenic Navy. Auxiliary machinery should be carefully selected with emphasis on low noise emission, high reliability, ease of access, and maintainability.
Provisions must be made to accommodate special operations forces (SOF) onboard. Crew accommodations should be modern and suitable for both sexes, ensuring comfort and operational readiness. Additionally, shore-based training simulators should be included in the overall program to support crew training and mission preparation.
New Submarine’s Weapons and Sensors
The platform will feature a comprehensive weapons suite, including torpedoes, anti-ship and land-attack missiles, and capabilities for special operations forces (SOF) deployment. In addition to soft- and hard-kill defensive systems, the submarine will also carry anti-air missiles and multiple UAVs capable of submerged launch. The Commodore stressed the need for design flexibility to accommodate future weapon systems and highlighted the critical requirement for long-term weapon producibility beyond initial vessel production.
Regarding electronic systems, the submarine must be equipped with an integrated combat management system, with individual subsystems configurable to meet the specific requirements of the Hellenic Navy. It should feature state-of-the-art acoustic sensors, including a towed array sonar, capable of operating across the full acoustic spectrum—from low to high frequencies—in both passive and active modes. In addition, cutting-edge non-acoustic sensors are required, with optional COMINT (communications intelligence) capabilities, and the ability to operate and integrate both Unmanned Aerial Vehicles (UAVs) and Unmanned Underwater Vehicles (UUVs). The communications suite must be highly advanced, incorporating standard communication channels (including VLF and cellular), as well as modern datalinks such as BWA and ECBs, alongside SHF and L-band SATCOM capabilities.
Procurement Procedure
The Greek Commodore confirmed that the high-level operational requirements for the new submarine program have already been approved, and Requests for Information (RFIs) were issued to reputable manufacturers as early as summer 2024. To support the evaluation process, the Navy has distributed a detailed questionnaire seeking specific information on existing submarine designs and proposals, allowing them to be assessed against the Hellenic Navy’s operational criteria.
Subsequently, the level of adaptability of each proposal to the Navy’s system-specific requirements will be thoroughly examined. It is also important to note that each proposal must include a comprehensive follow-on support plan—similar to that of the FDI HN program—and active participation of the national defense industry is considered mandatory (an indication that a number of the boats will be built in Greece).
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As of 2025, the next steps in the program include drafting the detailed technical requirements, incorporating feedback received from industry respondents. This will be followed by the approval of the overall program plan and corresponding budget allocation. The final step will involve issuing a formal Request for Proposals (RFP) to selected manufacturers.
