Türkiye’s naval modernization efforts, STM Savunma Teknolojileri Mühendislik ve Ticaret A.Ş. has begun sea trials for its first domestically developed unmanned autonomous underwater vehicle (UAUV), the STM Neta 300. Initially conceived in June 2023 to address the Turkish Navy’s pressing need for modern mine-hunting solutions, the Neta 300 marks a new phase in Türkiye’s journey toward naval autonomy and underwater warfare capabilities.
Developed in-house by STM, a key player in Türkiye’s defense industry, the Neta 300 is intended to strengthen the country’s undersea warfare capacity and reduce dependence on foreign systems. With the system now undergoing extensive sea trials in the Mediterranean following successful pool tests, STM is preparing to position itself as a leading exporter of underwater defense technologies.
The Neta 300 was engineered from the ground up to be versatile, modular, and field-ready for a range of naval operations. At just 2.7 meters long and weighing 70 kg in its base configuration, the vehicle is designed to be portable by two personnel and deployable from various surface vessels. The system’s modular structure allows for battery upgrades and payload flexibility, enabling it to adapt to different mission profiles.
Its compact size belies its sophisticated engineering. Propelled by a direct-drive brushless DC motor attached to a three-blade propeller, the Neta 300 uses fins for maneuvering and can achieve speeds of up to 5 knots, with a cruise speed of 3 knots. Its operational depth limit reaches 300 meters, aligning it with typical mission envelopes for mine countermeasures and underwater surveillance.
The Neta 300’s 2.1 kWh battery supports up to 12 hours of operation, while an upgraded 4.2 kWh pack doubles that to 24 hours, offering mission planners extended flexibility.
What distinguishes the Neta 300 from earlier remotely operated vehicles is its advanced autonomy and suite of onboard sensors. Navigation is managed through a combination of inertial navigation systems, Doppler Velocity Logs, altimeters, and GPS. Communication links include acoustic modems and Wi-Fi by default, with options to integrate Iridium, RF, and LTE systems for beyond-line-of-sight operations.
Mission planning and post-mission debriefs are supported by a dedicated STM software suite, which interfaces with the vehicle through external Ethernet and charging ports. Its marine-grade aluminum hull ensures durability in challenging underwater environments.
Sensor payloads play a pivotal role in its mine-hunting and reconnaissance capabilities. Equipped with side-scan sonar and gap-filling sonar, the Neta 300 can autonomously survey underwater environments and identify mine-like threats. Optional integration of synthetic aperture sonar (SAS) enables the system to deliver high-resolution imaging and extended detection ranges—capabilities critical for mine countermeasure (MCM) missions.
STM emphasizes that the Neta 300 isn’t just a mine hunter; it’s a multipurpose underwater asset. Leveraging its scanning and navigation systems, it can assist in Search and Rescue (SAR) operations by locating submerged wreckage or bodies in disaster scenarios.
While its primary mission aligns with the Turkish Navy’s defense doctrine, the Neta 300 has a broad dual-use appeal. The vehicle is capable of conducting Intelligence, Surveillance, and Reconnaissance (ISR), Rapid Environmental Assessments (REA), Explosive Ordnance Disposal (EOD), Anti-Submarine Warfare (ASW), and port defense.
Its civilian applications include geophysical surveys, environmental monitoring, marine archaeology, offshore renewable energy monitoring, and subsea pipeline inspections. STM offers a developer-friendly software kit, allowing third parties to integrate custom sensors and software payloads into the platform.
Payload flexibility is a major selling point. Standard options include forward-looking sonar, high-definition cameras with LED lighting, and sensors for sound velocity, pressure, and temperature—all crucial for adapting to various underwater tasks.
The Neta 300 made its public debut on October 22, 2024, during the SAHA EXPO defense and aerospace exhibition in Istanbul. However, it wasn’t alone.
Alongside the Neta 300, STM revealed the Neta 1000—a larger, more capable sibling designed for longer missions and increased payload capacity. At 5.4 meters in length and weighing up to 360 kg, the Neta 1000 pushes the boundaries of UAUV operations for Türkiye. While it shares the same propulsion architecture and cruise speed as the 300, it boasts a dash speed of 8 knots and endurance up to 55 hours, depending on its battery configuration.
The Neta 1000 is specifically designed for extended surveillance, deep-sea reconnaissance, and strategic missions requiring higher power and sensor capacity.
STM confirmed that both vehicles would support similar payloads and mission software, streamlining logistics and training for operators. The company also announced plans to participate in NATO’s 2025 REP(MUS) experimentation event—a multinational exercise dedicated to unmanned maritime systems—offering international exposure and evaluation under operational conditions.
STM’s vision doesn’t stop with the Neta 300 and 1000. The company has laid out an ambitious roadmap for a full family of underwater vehicles. This includes the lightweight Neta 100 for shallow water operations, expected to be especially valuable in confined or near-shore environments such as straits and ports.
Also in development is the Neta 600, positioned as a mid-range vehicle, which is expected to be introduced in 2025. However, the most ambitious project in the pipeline is STM’s Extra-Large Unmanned Underwater Vehicle (XLUUV).
This XLUUV will reportedly weigh between 10 and 12 tonnes, with a body length between 10 and 15 meters and a diameter of up to 1.5 meters. Capable of operating at ranges between 1,000 and 2,000 nautical miles, these strategic platforms are envisioned for deep-sea missions including the protection of undersea cables, infrastructure surveillance, and possibly even payload delivery.
The key enabler behind these larger platforms is autonomy—specifically, AI-based algorithms that STM is developing internally. These systems are being built using a spiral development approach, allowing STM to incrementally add features such as autonomous navigation, adaptive mission planning, and response to dynamic underwater threats or environmental changes.
In an exclusive statement, Gürkan Gezgin, STM’s Industrial Cooperation Manager and a former submarine officer in the Turkish Navy, emphasized that STM’s aim is not merely to meet current naval needs but to anticipate and shape future trends.
“AI-enabled underwater systems are not just supplementary—they’re transformative,” said Gezgin. “Over the next 10 to 20 years, we expect autonomous underwater vehicles to play a frontline role, working in tandem with manned submarines, or even operating independently in contested zones.”
While weaponization is a long-term consideration, STM acknowledges that widespread operational deployment—especially for armed versions—will hinge on user confidence in the system’s autonomy. For now, the focus remains on perfecting performance, building trust in AI-based control layers, and ensuring seamless integration with existing naval command and control systems.
Special forces delivery, long-range ISR, and covert underwater operations are all within the conceptual scope for future variants, according to STM. The modular design of the Neta family ensures that once confidence in autonomy grows, payloads and mission parameters can be scaled accordingly.
STM, a company with over 30 years of experience in Türkiye’s defense sector, operates in key areas including naval platforms, UAVs, command and control systems, AI, cybersecurity, and big data analytics. The development of the Neta vehicle family is closely coordinated with Türkiye’s Ministry of National Defense and the Presidency of Defense Industries (SSB), ensuring alignment with broader national strategy.
As of May 7, 2025, STM confirmed that a domestic sales contract for the Neta 300 had been signed—an early indication of confidence from the Turkish Navy. With continued trials underway, STM plans to complete operational evaluations before offering the platform to NATO allies and other friendly nations.
If successful, Türkiye could find itself competing with established defense manufacturers from the U.S., U.K., and France in the underwater robotics domain—an arena that has so far been dominated by a handful of global players.
STM’s approach—affordable, modular, AI-ready systems tailored to real-world operational needs—could offer a viable alternative to higher-cost Western systems for many countries looking to modernize their naval forces.
The introduction of the STM Neta 300 is more than a technological milestone—it represents Türkiye’s intent to lead, not follow, in the emerging domain of underwater autonomous systems. As geopolitical competition increasingly shifts underwater, with seabed infrastructure, undersea communications, and submarine warfare gaining new importance, STM’s innovations may shape how nations defend their interests beneath the waves.
In a world where mines can block straits, cables carry a nation’s digital heartbeat, and seabed surveillance is a new strategic frontier, STM’s underwater ambitions are not just relevant—they’re essential.
And as the Neta 300 glides silently through the Mediterranean on its sea trials, it may be signaling the beginning of a new underwater doctrine—not just for Türkiye, but for allied navies navigating an increasingly complex maritime future.
