Poland’s naval strategy: why midget submarines are not a viable alternative to conventional submarines

The necessity of conventional submarines in the Baltic Sea

For years, Poland has recognised the necessity of modernising its submarine fleet, and the Orka programme has been at the forefront of these efforts. The plan to acquire three full-sized conventional submarines with AIP technology accelerated after the escalation of hostilities in Ukraine, reflecting Poland’s heightened security concerns in the Baltic Sea region. A number of international shipbuilding firms, including Fincantieri, Navantia, Saab, Naval Group, and thyssenkrupp Marine Systems, have expressed interest in supplying Poland with state-of-the-art submarines. More recently, Korean companies such as Hanwha Ocean and Hyundai Heavy Industries have also proposed designs.

According to the latest Polish press reports, the competition has now narrowed to three contenders: Germany’s thyssenkrupp Marine Systems, Sweden’s Saab, and Italy’s Fincantieri. The Polish Ministry of National Defence has repeatedly emphasised that acquiring these submarines remains a top priority. However, an official timeline and contract signing date have yet to be publicly disclosed, adding uncertainty to the programme’s future.

The rising interest in midget-class submarines

Despite the strategic significance of full-sized submarines, Poland’s recent interest in acquiring midget-class submarines has sparked concern. In February, a high-ranking Polish delegation, including the Deputy Minister of National Defence and the head of the Armament Agency, visited Italy’s M23 S.R.L. shipyard in Bergamo. The company, in collaboration with GSE Trieste, produces the M23 C-series of midget submarines, which have reportedly been considered for acquisition by Poland.

The visit raised speculation that Poland might prioritise the procurement of midget submarines as an interim solution or even as a replacement for conventional submarines. This possibility has alarmed naval experts, as midget submarines cannot provide the full operational capabilities required to secure Poland’s maritime interests in the Baltic Sea.

The capabilities and limitations of midget submarines

Midget submarines offer certain advantages in specific scenarios. Their small size and low acoustic signature make them difficult to detect, and their high manoeuvrability allows them to operate in shallow waters and confined spaces. These characteristics make them useful for reconnaissance missions, intelligence gathering, and special operations deployments, particularly for inserting and extracting special forces in covert missions.

The M23 C-series, for example, has been designed with some offensive capabilities, including the ability to launch 533mm heavyweight torpedoes. It also features limited seabed reconnaissance capabilities, allowing it to conduct mine detection and disposal operations. Additionally, the cost of acquiring and maintaining midget submarines is considerably lower than that of conventional submarines, making them a budget-friendly option for countries looking to expand their underwater assets.

However, these advantages come with significant trade-offs. Midget submarines have major limitations in endurance, range, and operational scope. Unlike conventional submarines, which can remain submerged for extended periods thanks to AIP technology, midget submarines require frequent surfacing for refuelling and battery recharging, limiting their ability to conduct prolonged operations. Their small crew size—typically around 10 to 15 personnel—restricts mission sustainability, as all crew members must be actively engaged in operations, leaving little room for extended shifts and onboard maintenance.

Furthermore, midget submarines lack the sophisticated sonar and combat management systems of full-sized submarines. Their reduced sensor capabilities significantly impact their ability to detect enemy submarines or surface vessels at long ranges. Additionally, while they can carry torpedoes, their limited firepower and smaller payload capacity make them ineffective for full-scale naval combat. In a direct confrontation, a midget submarine would be at a severe disadvantage against conventional enemy submarines or advanced anti-submarine warfare (ASW) platforms.

Why midget submarines cannot replace conventional submarines

While midget submarines can serve valuable niche roles, they cannot replace conventional submarines for several key reasons. The Baltic Sea presents a complex operational environment that requires submarines with long endurance, advanced sonar capabilities, and a diverse weapons loadout. The ability to conduct covert operations deep within contested waters, launch strategic strikes, and engage enemy naval forces at long range is paramount.

Conventional submarines are designed for multi-role operations, including anti-submarine warfare, anti-surface warfare, electronic warfare, intelligence operations, and special forces deployment. They provide the endurance and firepower needed to maintain deterrence and protect national interests. The Polish Navy’s participation in NATO operations also necessitates interoperability with allied forces, something that conventional submarines are designed to support. Midget submarines, by contrast, lack the endurance, offensive capability, and strategic flexibility required for these roles.

Additionally, replacing conventional submarines with midget-class alternatives would compromise Poland’s ability to conduct independent submarine operations. While midget submarines can complement a fleet by fulfilling specific tactical roles, they are not suitable for long-range patrols, sustained intelligence missions, or engaging in full-scale naval conflicts. Given the growing threat from Russia’s submarine fleet, Poland needs a robust underwater force that can provide a credible deterrent.

The training and operational readiness factor

Another critical issue is the training of submarine crews. Conventional submarine operations require years of rigorous training and experience in deep-water and combat environments. The Polish Navy needs to ensure that its personnel are fully prepared to operate complex underwater platforms. Training on midget submarines would not provide the necessary experience for full-sized submarine operations, as the operational environments and tactical requirements differ significantly.

Poland’s future naval strategy

Poland must remain committed to acquiring conventional submarines under the Orka programme to ensure its long-term maritime security. While midget submarines could serve as auxiliary assets for special operations and intelligence gathering, they should not be viewed as substitutes for full-scale combat submarines. The Polish government must prioritise operational effectiveness over short-term cost savings and ensure that any investment in midget submarines does not come at the expense of the Orka programme.

In a region where naval power is becoming increasingly crucial, Poland needs submarines that can project force, maintain deterrence, and protect national interests against evolving threats. Conventional submarines remain indispensable for securing Poland’s maritime domain, contributing to NATO’s strategic defence posture, and ensuring stability in the Baltic Sea and beyond.

While midget submarines may provide additional flexibility in select missions, they cannot replace the strategic depth and combat capabilities of full-sized submarines. The Polish Navy must focus on securing advanced, full-capability submarines that can meet the operational demands of modern naval warfare, ensuring that Poland remains a formidable maritime power in the years to come.