**OVERVIEW:** The PL-865 *Losos* [Piranha] is a specialized Project 865 midget submarine operated by the Russian Navy.

**DETAILS:**

The Project 865 *Losos* (Salmon) submarine was a unique design conceived in the late Soviet era to fulfill a specific set of clandestine underwater operational requirements. Development was initiated in the 1970s, with the design bureau tasked with creating a small, highly maneuverable submarine capable of operating in shallow waters and executing covert missions. The *Losos* design philosophy emphasized stealth, utilizing advanced noise reduction techniques and a compact profile to minimize detection. Its primary purpose was to insert and extract special forces units, conduct reconnaissance, and potentially lay underwater mines or perform other clandestine operations in littoral environments. The construction of the *Losos* reflects a focus on advanced materials and construction techniques to ensure both durability and acoustic signature reduction. A single unit, PL-865, was completed.

The operational role of the *Losos* is centered on special operations and covert activities. Given its size and sensor suite, it is unlikely to be involved in traditional anti-submarine warfare (ASW) or anti-surface warfare (ASuW) roles beyond self-defense. Instead, its strength lies in its ability to operate undetected in shallow waters, a capability crucial for inserting and extracting special forces teams, conducting seabed reconnaissance, and potentially deploying specialized equipment. Its limited endurance restricts its operational range, suggesting it is primarily designed for operations in coastal regions and confined waters.

The PL-865 is equipped with a sensor suite tailored for its specific operational profile. The "Quad Loop DF" likely provides direction finding capabilities, enhancing situational awareness in congested environments. The "Squid Head" sonar (identified as MRP-25) serves as the primary active sonar, providing detection and tracking of underwater contacts, while "Snoop Tray 2" (MRK-50 Kaskad) likely contributes to electronic support measures (ESM), detecting and analyzing enemy radar emissions. The Generic Submarine Periscope, Optical provides a traditional visual observation capability, essential for navigation and target identification in shallow water environments. The presence of 533mm torpedo tubes suggests a self-defense capability, potentially employing anti-submarine or anti-surface torpedoes. The small size of the submarine likely limits the torpedo payload to a very small number, emphasizing covertness above offensive firepower.

**SPECIFICATION:** Length: 28.2 m || Beam: 4.74 m || Draft: 3.9 m || Disp: 218 t

**SENSORS:** Quad Loop DF || Squid Head [MRP-25] || Snoop Tray 2 [MRK-50 Kaskad] || Generic Submarine Periscope, Optical

**ARMAMENT:** 533mm TT