UUVs (Unmanned Underwater Vessels) have been around for decades, mainly for scientific research. Ukraine, finding that their attack USVs (Unmanned Surface Vessels) were vulnerable to Russian heavy machine-gun fire before the target ship could be hit, decided to try attacking from underwater. This led to the rapid development of the Toloka TLK-150 UUV. There are already torpedoes that can use sensors or remote control via a wire that connects the torpedo with its launcher (a sub or surface ship). The torpedoes are larger, bulkier and more expensive than the TLK-150. The TLK is smaller and more maneuverable than guided torpedoes. The TLK-150 is not intended for attacks but for reconnaissance. To do this it has a long mast that operates like a periscope but contains a digital video camera with night vision to record what is nearby. TLK-150 can be remotely controlled or operate autonomously using GPS. At night the small mast is nearly invisible as it leaves a small wake when moving and no wake at all when it is stationary.
There are three models of the battery powered TLK. The TLK-150 is 2.5 meters (eight feet) long, has a range of up to 100 kilometers and top speed of 20 kilometers an hour. Payload size is 20-50 kg (44-110 pounds) depending on battery size. A larger battery provides more range. The TLK -150 can be used for reconnaissance (for enemy targets or underwater minefields). In attack mode the TLK will approach slowly, usually at night when the small “periscope” containing the video camera and communications antenna is nearly invisible to enemy eyes or surface radars. Sonars would also have a hard time detecting the TLK-150 because the silent electric motors power two propellers, one on each “wing” of the TLK.
Ukraine is testing the TLK-150 and may build a lot more of them if it performs as expected in the Black Sea. If an armed TLK-150 is able to attack Russian warships, that will change the naval balance in the Black Sea. The Ukrainian use of armed UAVs and USVs against Russian ships has been a mixed success because the Russians can spot these and use auto-cannon and heavy (12.7mm or 14.5mm) machine-guns to destroy the attackers, even during night attacks.
There two larger TLK designs proposed; the TLK-400 with a range of 1,200 kilometers and a half ton payload. The TLK-1000 has a range of 2,000 kilometers and a five ton payload.