Historical Background

There is no concrete evidence to date to prove who designed the first submarine. However, it is understood that various underwater vehicles were attempted to be constructed between 332 BC and the 18th century, some of which were legends told from word of mouth and some were unfinished designs [1]. It is noted that submarines were initially designed by William Bourne in 1578; however, his boat was not tested [2]. A similar one was later trialed by Cornelius Jacobszoon Drebbel in the Thames River in 1620, but the British Naval Ministry did not adopt it as a weapon [3]. For this reason, it is generally accepted that the first submarine used in warfare was David Bushnell’s “Turtle,” which he built in 1775 [4]. Inspired by a fish called Torpedofish, Robert Fulton designed the submarine “Nautilus” and, using an electric shock, successfully killed its enemy. He named the weapon, now known as a sea mine, “Torpedo” [5]. In 1880, the Swedish Nordenfelt developed a submarine produced by British engineer William Garrett, achieving an underwater speed of 14-15 knots [6].

Despite these advancements, the consensus credits John Philip Holland with inventing the first modern submarine. [7]. While the widely accepted timeline for submarine design aligns with the mentioned developments, as Seyyid Vehbi noted in his work “Surname-i Humayun”, there is an intriguing historical account. In 1719, approximately 56 years before the Turtle submarine, the Ottoman Chief Architect El-Hac Ibrahim Agha designed an underwater vehicle resembling a crocodile for Sultan III Ahmed Khan’s circumcision ceremony in Istanbul. This vehicle was capable of diving, surfacing, undergoing in the water, and anchoring like a ship. Although it added great excitement to the celebrations, it also indicated an early implementation of a design similar to the Turtle submarine [8].

The submarine named “Resurgam,” built by George William Garrett in Birkenhead in 1879, sank off the coast of North Wales while being towed to Portsmouth, England. Thereupon, Garret moved to England and established a partnership with Nordenfelt Gun and Ammunition Company Limited. Although the official production of the Nordenfelt submarine started in 1870, a submarine that could launch torpedoes was developed by Garret in Stockholm, Sweden, in 1885, considering the design features of the “Whitehead” torpedoes used on surface ships at that time and the Resurgam submarine [9]. The name of this new submarine, which can launch torpedoes via two 355 mm tubes and fire two 35 mm machine guns on the surface, was Nordenfelt-I. The Ottoman Attaché Major Halil Bey in Berlin participated in Nordenfelt-I’s first sea trials, and in his report, he stated that this submarine could not meet the operational requirements.

After Greece purchased the Nordenfelt-I submarine, Ottoman Sultan Abdulhamid II perceived this situation as a threat. Garret was invited to Istanbul and an agreement was signed between the Nordenfelt Company and the Ottoman Naval Ministry for the construction of two submarines that could fire three torpedoes on 23 January 1886. Although the Ottoman submarine Abdülhamit (Nordfelt II), produced on the Valide (Empress) slipway in Kasımpaşa-İstanbul, was launched on 6 September 1886, diving trials were only made in February 1887 [10]. Since Greece’s project was not successful, the Ottoman submarines Abdülhamit and Abdülmecit went down in history as the world’s first torpedo-launching submarines, despite their technical inadequacy, their inability to be used in any war, and being left to rot in the Golden Horn (Haliç) until 1910.

First Use of Submarines in Warfare

The first use of submarines as an effective combat vessel was demonstrated in World War I, when the British battleships HMS Aboukir, HMS Cressy and HMS Hogue were sunk by the German submarine U-9 (Type IIB) and 1,459 combatants were killed on the morning of 22 September 1914. Also, the Battle of Gallipoli introduced a significant submarine threat to the Mediterranean, Turkish Straits, and the Black Sea. This event marked a transformative moment in naval warfare, altering its dynamics permanently. Strategically, naval vessels, particularly submarines, demonstrated an exceptional capacity for surprise, thereby wielding the potential to decisively influence the course of warfare. This capacity extended the ability to inflict substantial casualties on opposing units, solidifying submarines as historical actors on the naval stage. Consequently, no subsequent naval battle could be viewed through the same lens, given the profound impact of submarines on the nature and outcomes of such engagements.

In the realm of submarine warfare, the preeminent figure that immediately commands attention is Grand Admiral Karl Dönitz of Germany. He played a pivotal role in shaping historical trajectory and changing paradigms, especially in managing submarine warfare [11]. In 1916, Karl Dönitz assumed the role of a submariner, progressing to the position of a submarine commander in 1918. His notable assignment involved the interception of a British convoy transiting westward through the Suez Canal. Stationed with his submarine around Malta in September, Dönitz faced the challenge of formulating a plan to locate and engage the designated targets collaboratively. This endeavor was part of an inaugural attempt at a joint attack strategy involving another submarine under the command of Stenbauer. Given the technological limitations of the era, including restricted submarine submersion durations and deficient communication infrastructure, executing a coordinated bilateral submarine operation was deemed nearly impractical. The inherent constraints of the period, encompassing communication deficiencies and the limited submerged endurance of submarines, rendered the successful execution of such joint operations a considerable challenge [12].

In another operation, Dönitz identified a significant presence of military vessels escorting a sizable convoy originating from China and India. Despite the advantageous visibility provided by moonlight, which illuminated both the warships and the convoy’s ship silhouettes, making nighttime operations more feasible, challenges arose within the context of the British-developed zig-zag plan. This tactical maneuver aimed to impede submarine attacks by altering the convoy’s course and speeds at specified intervals [13]. After considerable exertion, Dönitz successfully targeted the largest vessel in the convoy’s second column. However, the submarine faced a formidable challenge when subjected to depth charge attacks near the sunken ship, causing a tumultuous confrontation between the submarine and escort vessels. Despite Dönitz’s initial intention to conduct attacks from periscope depth, exploiting the advantage of submarine operations under the cover of night, unforeseen technical issues compelled an emergency surfacing. The malfunction resulted in battery acid overflow, rendering the submarine incapable of submersion. Forced to remain surfaced, the submarine became vulnerable to attacks from surface ships, ultimately leading to its capture by the British, along with its crew [14].

Drawing upon insights garnered from these operations, Karl Dönitz deduced that submarines could exhibit effectiveness under nocturnal conditions. Moreover, he discerned the strategic advantage of orchestrating attacks on substantial convoys using a maximal deployment of submarines. Nonetheless, it remains an incontrovertible reality that coordinating and overseeing multiple submarine assaults proved exceedingly challenging given the technological constraints inherent in submarines during that era. The rationale behind the decision to conduct large-scale submarine attacks emanated from the notion that, in the face of a sizable assemblage of enemy convoys and their accompanying escort vessels, the efficacy of a singular submarine in sinking multiple ships would be insufficient. Consequently, the more judicious approach would involve leveraging a considerable number of submarines to inflict substantial casualties upon the convoy. Failing to adopt such a strategy would inevitably lead to the acknowledgment that, barring a few sunk vessels, the remainder of the enemy convoy would have successfully executed its operations.

Upon the conclusion of Grand Admiral Dönitz’s internment in 1919, the German Navy inquired about his willingness to resume his duties. In response to the inquiry regarding the feasibility of reintroducing submarines, Dönitz, alluding to the restrictions imposed by the Treaty of Versailles, posed a counter-question. Despite accepting the assignment, he continued his service on surface ships, as submarines were not permitted to be included in the German Navy’s inventory until 1935. Eventually, Dönitz assumed command of the cruiser Emden. The necessity arising from the prohibition of submarine construction by Article 191 of the Treaty of Versailles on 28 June 1919, presented an opportunity for Dönitz to acquire profound expertise in both submarine and surface operations. This dual experience allowed him to discern the vulnerabilities inherent in each type of operation, leading to the development of more sophisticated tactics. Simultaneously, he actively contributed to formulating the algorithms guiding technological advancements aligned with operational requirements.

A transformative shift occurred with the signing of the Anglo-German Naval Treaty on 18 June 1935. This agreement granted the German navy the prerogative to possess up to 35% of the tonnage of the British navy. Consequently, Dönitz could now actively pursue the integration of submarines into the German naval inventory, marking a significant departure from the constraints imposed by the Treaty of Versailles. Through this agreement, Germany adeptly deceived even diplomatically seasoned nations such as the United Kingdom, thereby establishing the groundwork for constructing 250-ton submarines in accordance with the terms outlined. In World War I, Germany successfully completed the construction of 334 submarines, and in World War II, this number escalated to a total of 1,162 submarines.

The submarines, known as U-Boats (Unterwasser Boat), played a pivotal role in naval warfare. During World War I (1914-1918), these submarines were responsible for the sinking of 10 million gross tons (GRT) of ships. However, in World War II, the relentless efforts of the Allied Forces, employing both land-based Maritime Patrol Aircraft and Surface Ships, resulted in the sinking of 632 out of the 1,162 German submarines at sea. The fate of the remaining submarines varied, with some being destroyed on land and others deliberately eliminated to prevent them from falling into the hands of the Allied Forces [15]. Nevertheless, German submarines inflicted substantial damage on the Allied forces, destroying 175 warships and 2,825 merchant vessels. The toll included an extensive loss of deadweight tonnage, with approximately 14.1 million gross register tonnages (GRT) of ships, equivalent to around 70% of the Allied forces’ naval capacity, succumbing to the attacks orchestrated by German submarines [16].

While there may be variations in the tonnages and the reported number of ships sunk across different sources, the undeniable reality remains that the naval conflict during this period was monumental. The heightened casualty rates witnessed in World War II can be attributed to the rapid technological advancements that characterized this era. The dynamic landscape of technological warfare played a pivotal role in determining the outcomes of naval engagements. During this period, surface ships and air vehicles sometimes emerged victorious, while, conversely, submarines endured substantial losses. The interplay of evolving technologies significantly influenced the strategies and outcomes of naval warfare during World War II. Critical factors influencing the dynamics of naval warfare during the war included the implementation of strategic advancements such as integrating snorkel systems into submarines and outfitting surface ships with radar devices. These innovations played a pivotal role in shaping the course of engagements at sea. The introduction of snorkel systems, allowing submarines to operate submerged while still taking in air, increased their stealth and endurance.

On the other hand, equipping surface ships with radar technology significantly enhanced their ability to detect and respond to potential threats. Additionally, the rapid response of aircraft stationed on carriers to identify and counteract submarines contributed to the complexity of naval operations. These technological adaptations underscored the dynamic nature of naval warfare during this period, with advancements in both offensive and defensive capabilities reshaping strategies and outcomes at sea. Irrespective of the underlying causes and ultimate outcomes, the German Navy’s resilience against the two largest navies in the world, coupled with its notably effective submarine operations, exhibited an asymmetrical yet productive character. The success of these naval endeavors was not merely happenstance; rather, it was underpinned by well-conceived logistical and technical support that operated discreetly behind the scenes of the war. This orchestrated support played a crucial role in sustaining and amplifying the effectiveness of the German Navy’s operations in the face of formidable adversaries.

The success of submarine operations was decisively influenced by a meticulous consideration of the requirements of the Land Forces engaged in rigorous warfare, the necessities of the Air Forces providing close air support to both Land and Naval Forces, and occasionally conducting air attacks on specified targets independently. Furthermore, the realization of projects aimed at addressing the operational needs of the Naval Forces, coupled with diligent efforts in planning and allocating the budget, played a pivotal role in the overall success of submarine operations. This integrated approach ensured a comprehensive alignment of resources with strategic objectives, contributing significantly to the effectiveness of submarine warfare.

Concept of Current Submarine Operations, Weaknesses, and Requirements

The fundamental rationale behind the existence of submarines lies in their intrinsic attributes of silence and secrecy. Unless technological advancements negate these pivotal characteristics in the future, submarines will persist as a significant component of naval warfare. In contrast to surface vessels, which actively search for, locate, and engage their targets akin to lion hunting, submarines adopt a more strategic approach by casting their metaphorical webs like spiders, patiently awaiting their prey. Consequently, the operational doctrine governing submarines diverges considerably from that of surface platforms. Advancements in technology not only extend the operational lifespan of submarines but also broaden their sphere of influence. However, this expansion necessitates the acquisition of data from external sources. Remarkably cost-effective when compared to surface ships, submarines exhibit prolonged self-sustainability during crises without requiring frequent resupply at designated stations. Their extensive cruising range renders high speeds unnecessary, except when evading adversaries. Armed with formidable weaponry, submarines possess the capability to deliver substantial blows to the enemy, thereby disrupting their planned operations.

This unique proficiency empowers submarines to alter the course of conflicts by strategically deploying at opportune moments and locations, inflicting significant damage on opposing forces, and attempting to exploit vulnerabilities. Moreover, submarines can disrupt the logistical transportation of enemies, as observed in the two world wars. The strategic deployment of submarines has the potential to profoundly influence the outcome of warfare, enabling them to exploit the weakest points of adversaries while fortifying friendly forces in positions of strength. Submarines have a very high deterrent feature. Just as no one may want to jump into a pool and swim if they know there is a crocodile in it, no naval vessel wants to knowingly pass through the submarine patrol area. All anti-submarine warfare operations, excluding air assets, in the vicinity of the submarine patrol area will result in the favor of the submarines, and the enemy will suffer heavy losses. However, conventional submarines have air-dependent propulsion. It must rise to at least periscope depth either due to the need for fresh air for its personnel, to charge its batteries, or to establish communications. Due to the dependence of submarines on air, the snorkel mast, periscope, and communication antennas may lead to their detection and identification. Since secrecy and silence will be broken at these critical moments, the survival of the submarines will be at risk.

Drawing from Admiral Dönitz’s experiences in both the two world wars, the emergence of the concept advocating submarine operations in accordance with the wolf pack paradigm gained prominence. Despite advancements in contemporary technology, a capability suitable for this purpose has yet to be developed. Consequently, submarines currently operate autonomously. However, given their coexistence with friendly surface elements within the same operational theater, the establishment of either an organic or inorganic connection becomes imperative. It is essential to underscore that submarines do not merely serve as support elements; rather, they may encounter circumstances necessitating their direct involvement in support operations, despite certain existing technical challenges. Presently, the most viable modality for joint operations involves coordinated submarine operations. The efficacy of such operations would be significantly enhanced if submarines, surface ships, or command and control centers could maintain uninterrupted communication, preserving the secrecy integral to submarines while facilitating effective collaboration with surface ships, thereby augmenting strike power.

However, the prevailing necessity for measures to prevent mutual interference, the imperative to share the operational area, and the need for strategic force repositioning at specific times and locations render the realization of the wolf pack concept unfeasible. Conversely, the implementation of coordinated submarine operations introduces inherent risks to the survival of submarines, demanding careful consideration of the delicate balance between operational effectiveness and the preservation of submarine secrecy. When submarines initiate offensive actions by deploying their torpedoes and guided missiles against adversaries, their immediate disposition becomes inherently transparent. Consequently, naval and sea-air elements acquire the capacity to launch a coordinated anti-submarine operation, effectively thwarting potential submarine threats to high-value units (HVUs) by diverting them from their intended routes.

The survivability of submarines is contingent upon their ability to engage targets beyond the visual horizon, given the contemporary landscape of advanced reconnaissance and surveillance systems coupled with the existence of lightweight torpedoes. The vulnerability of submarines, particularly those with diminished battery capacity, is underscored by their reliance on surfacing to periscope depth for battery recharging. This exposes submarines to potential detection, particularly during maneuvers aimed at evading armed reconnaissance elements situated around the datum of the submarine. In dire circumstances, submarines may contemplate resorting to extreme measures, including the consideration of suicide attacks, paralleling the behavior of a whale intentionally beaching itself, or they might be subjected to actions that lead to their self-destruction.

Despite their present vulnerabilities, submarines persist as a potent, deterrent, and strategically vital force in the modern technological ecosystem. Nevertheless, following future technological advancements, conventional submarines may lose their ability to generate surprise as effectively as in the past. New designs and operational capabilities of submarines should be carefully considered, and caution should be exercised before investing in existing technologies so that submarines can evade anti-submarine warfare (ASW) units.

Assessment of the Future Role and Operational Requirements of Submarines

As technological advancements progress, submarines must enhance their silence and stealth capabilities. Since military components of satellite systems, radar and sonar systems, advanced sonobuoys, and sensors of maritime patrol aircraft (MPAs) and helicopters, temperature, pressure and salinity changes of the sea and magnetic anomalies in operation areas allow detection more easily, submarines need to dive deeper. Therefore, remote sensing systems, weapon systems, and communication systems need to be evolved, and dependency on air needs to be reduced. As the relative technological superiority between surface and air vehicles and submarines shifts, a situation emerges in favor of the former. However, since nature is the biggest friend of submarines, the secret cover of nature provides an advantage predominantly in their favor. In the future, the development of artificial intelligence (AI), robotics applications and unmanned weapon systems will significantly affect submarine operations.

The raison d’être of submarines lies in their role to prevent, impede, and dissuade hostile naval vessels with the intention of establishing sea control within a designated operational area. Contemporary technological advancements enable research submarines to reach depths of up to 11,000 meters. Nevertheless, current technological capabilities point out that submarines do not necessitate navigating at depths exceeding 1,000 meters at this juncture. Oceanographic and meteorological conditions favor submarine operations. Variations in temperature, pressure, and salinity rates corresponding to different depths result in distinct layers within the water body. Submarines capitalize on the acoustic patterns by concealing themselves beneath these layers. Moreover, the presence of plankton induces reverberation, resulting in the formation of an insulating layer that hinders underwater acoustic propagation and effectively conceals submarines. The least favorable acoustic conditions for submarines are characterized by isothermal and isovelocity conditions. Submarines exhibit vulnerability to detection by surface units from an extended range under such circumstances.

Cavitation – creation of vapor bubbles within water in areas of reduced pressure around the propeller – induces a spectrum of challenges for both propulsion and control equipment in submarines, encompassing unpredictable flows, thrust breakdown, unsteady loads, vibration, noise, and metal erosion. The acoustic environment and soundscapes can be influenced by factors such as depths shallower than 200 meters, proximity to the shore, and the bottom topography (mud, sand, rock, etc.). As the operational depth of the submarine increases, the cavitation is mitigated. Intensive efforts are executed by naval units to detect and identify submarines by variable depth sonars (VDS) and sonobuoys. In necessity, a submarine is capable of landing on the seabed to evade ASW units. By virtue of this capability, she can keep its battery charged for a long time and deceive the enemy or hide from the enemy by giving the appearance of a rock. Since sitting at the bottom has both advantages and disadvantages, it is vital to make the right decision at the right time. A submarine sitting on the bottom may have difficulties using torpedoes against her target units, or if it is raided, it may be delayed in getting out of the bottom, approaching the target units at appropriate operational depth again, and assaulting an attack.

As a result of the improvement of Nuclear, Air Independent Propulsion (AIP), and conventional submarines, battery charging times are shortened and air-independent duration is extended, but they eventually have to come to periscope depth and obtain fresh air needed by the crew to meet the communication requirements, eliminate location errors, update the tactical picture within the horizon by internal sensors, or maintain the tactical or operational picture beyond the horizon by receiving data from third parties. These necessities jeopardize the secrecy element of submarines. Although almost 80 years have passed since Admiral Dönitz’s thoughts on the wolf pack concept, the development of new technologies to eliminate the weaknesses of submarines has not been as fast as expected.

The common thought of many experienced admirals who served on surface ships and eventually managed to be promoted to Commander of the Naval Forces was that “the force I cannot manage under my command is not mine”. Since it is not possible to conduct communication with a patrolling submarine under periscope depth at any time and assign a new task to that submarine in the absence of effective communication, an inadvertent attack made by the submarine commander as a result of a wrong decision may impede the commencement of the war at the most unexpected place and time. This is the most undesirable situation since the submarine may not be aware of the end of the war or the declaration of a ceasefire. The capability to command, control, and coordinate a submarine within an integrated structure is directly correlated with the efficacy of the communication systems. Indeed, no coach would aspire to place a boxer in the ring who is blind, deaf, and mute, recognizing the inherent challenges and limitations such a condition would impose.

Furthermore, due to its limited battery capacity, a submarine detected while snorkeling encounters significant challenges in executing evasive maneuvers, concealing herself, and disengaging from the datum. Given current technologies, it will be an inevitable result that a submarine detected in a confined area will have to attack the surface units, akin to a cornered cat lashing out desperately rather than attempting evasion. Conventional submarines patrolling at low speeds in operation areas allocated have difficulty shifting to prompted places at the desired time under dynamic acoustic and propagation conditions. In the future, all these problems will be resolved, and submarines will be much more effective and dynamic. Thanks to the laying of transoceanic fiber optic systems on the seabed, submarines will be included in real-time pictures with friendly forces in the same organic structure and establishing sustainable communications with the submarine. Thereon, enhancing coordination with surface and air units effectively, and the execution of direct support operations without encountering issues will become possible.

With significant advancements in battery technologies, it is anticipated that submarines’ batteries will be capable of rapid charging in the future, consequently reducing the risk of encounters with opposing units. Since it will be possible for submarines to attack air units soon, air units will not be able to easily execute ASW operations over submarine patrol areas. Thus, remote sensing technologies will come to the fore. While submarines can launch their torpedoes to mid-range distances today, in a short time, with developing technology, they will have the ability to launch hypersonic torpedoes to distances of up to 200 nautical miles (NM). Therefore, rather than undertaking an intruder mission to infiltrate an enemy’s force-protected naval bases, engagements can be initiated from the vicinity of the naval base upon landfall. In the future, submarines will have the capability to engage detected targets by employing the unmanned aerial vehicles they carry, extending their reach beyond the horizon.

A significant drawback of submarines lies in the vulnerability of their guided or ballistic missiles to detection and neutralization by the enemy’s air defense systems. Submarine weapons equipped with technologies enabling deception of air defense systems, along with the ability to receive a Common Operational Picture (COP) and Common Tactical Picture (CTP) while being in enemy airspace, will be incorporated into the inventory. The high-tensile and high-strength steels employed in submarines will be substituted with considerably more flexible and durable nanomaterials and alloys. Consequently, submarines will possess the ability to achieve greater depths, exhibit flexible movements akin to those of fish, and enhance their evasion capabilities for submarines, objects, surface ships, or weapons. Moreover, submarines will be equipped with special biomimetic sensors, paint, or coatings on their hull, resembling fish scales or fins, enabling them to detect hostile submarines at a defined distance and activate self-defense measures.

Submarines necessitate the integration of environmentally friendly (green) nuclear-powered propulsion systems. To achieve this, nations possessing submarines must adopt green nuclear technology, a matter that is poised to give rise to a distinct political contest. While air-independent propulsion (AIP) systems have not yet demonstrated their effectiveness to the extent of nuclear-powered submarines, their perceived relative advantage over conventional submarines is not fully satisfactory. Both logistical challenges and operational constraints underscore the indispensability of nuclear-powered systems. The development of countermeasures such as defensive weapons, decoys, or jammers against submarines raises the potential for the suppression of submarine capabilities. However, despite this, the weapons and sensors designed for submarines are expected to effectively engage surface ships, leveraging their superior range without the need to enter the ASW units’ engagement zone. As a result of mutual technological competition, it is highly likely that submarines will be converted to unmanned vessels in the medium and long term. There is no need for oxygen in an unmanned submarine and there is no need for food, accommodation, or any other humanitarian conditions. Thus, the submarine will turn into a smart weapon.

The algorithm of AI to be loaded into this weapon is very important. Upon successful establishment of communication with the submarine, it is of vital importance that the vessel navigates autonomously, adhering to its internal guidance system, precisely directing itself towards the designated target, and avoiding any inadvertent or erroneous engagements. Consequently, light displacement tonnages and large quantities of unmanned submarines can be effectively managed either through the coordination of Commander Task Groups (CTGs) or from strategically positioned land-based operations. The extension of the torpedo range up to 200 nautical miles will significantly complicate the management and control of maritime domains, as well as the coordination of weapons. Submarines, capable of engaging targets illuminated by surface and air units from great distances, necessitate their continuous integration into the tactical framework. Therefore, the ability of submarines to discern between friend and foe and not merely gain contact but also accurately detect and identify opposing forces becomes crucial.

To ensure optimal functionality in engagements with terrestrial targets, it is imperative to enhance the guided missiles’ capacity to detect, locate, and neutralize their designated targets. This necessitates the augmentation of the guided missiles’ diameter and the incorporation of a greater quantity of explosive ammunition within them. By doing so, the resultant increase in explosive payload serves to amplify the damage radius, thereby contributing to the heightened effectiveness of the guided missiles. Therefore, larger tubes or launchers are required to accommodate these enhanced missile specifications. By leveraging advancements in submarine sensor technology and the ability to receive tactical information from external sources, the designated submarine patrol area (SPA) will be thoroughly monitored without dependence on external support. This capability will be realized through the integration of unmanned aerial vehicles (UAVs) within submarines. In this context, a minimal number of conventional submarines will effectively cover a significantly expanded operational area, specifically extending to dimensions of 200X200 nautical miles, in contrast to the more constrained coverage of 45X45 nautical miles. The increased coverage will be made possible by the autonomous capabilities of the UAVs embedded within the submarines.

Conclusions 

While forecasting the future operational environment poses challenges, submarines will continue to hold strategic significance. It is crucial to underscore that technological leaps are progressing in favor of submarines. However, advancements in satellite systems, unmanned vehicles, and the augmentation of communication capabilities extending to the seabed will inevitably prompt a continuous reevaluation of the rationale behind the existence of submarines at each stage. The evolving technological landscape necessitates a constant examination of submarines’ relevance in the face of emerging capabilities in surveillance and communication. Upon achieving the capability to communicate with unmanned systems underwater, dormant weapons and systems submerged beneath the surface will be activated, endowed with intelligence surpassing traditional mines and possessing enhanced mobility. Reduced in size, unmanned submarines will be transportable by surface platforms, integrating seamlessly as organic components. These submarines will exhibit the versatility to execute predetermined tasks, transitioning to internal guidance when required, thereby enhancing their operational effectiveness.

Submarines are unlikely to serve roles in sea control or maritime dominance. Yet, their utilization for purposes other than strategic objectives may not be deemed appropriate unless they are unmanned. In the contemporary technological landscape, submarines are strategically positioned beneath or in proximity to high-value units (HVUs) of opposing naval forces. However, as the capability to engage these valuable targets from significant distances becomes feasible soon, warring parties will confront a complex and hybrid war environment. This environment will be characterized by uncertainty regarding the origin and timing of potential threats, challenging the strategic calculus of the involved parties. The concept of a cyber homeland is poised to strengthen further. With the theater of operations expanding significantly towards the space domain, naval operations will be conducted more effectively through improved C6ISR systems (Command, Control, Communications, Computers, Cyber-Defense and Combative Systems). Consequently, submarines must integrate into C6ISR systems. In essence, overcoming or minimizing technical challenges related to submarine management, communication, weapon and sensor systems, periscope depth, and air dependency, which troubled Admiral Dönitz, will propel submarines to an even greater strategic significance.

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