Recently, the media has been publishing a lot about very large unmanned marine drones (weighing more than 10 tons), or so-called unmanned underwater vehicles. Russian military historian Dmitry Boltnikov points out that many countries, such as the United States, Japan, the two Koreas, Malaysia, and Russia, produce such vehicles. According to him, the most famous of the very large Russian vehicles is the “Poseidon”, which is considered a “doomsday weapon”, which means that in the event of a nuclear attack, the Poseidon would have to reach American soil and cause an atomic explosion, resulting in a radioactive wave of enormous size, Sweeping everything in its path. The mass of "Poseidon" is 100 tons, its length is 25 meters, it can dive to a depth of one kilometer underwater, and its speed is 60-70 knots. It can transport different payloads, and thanks to its engine, it can stay and work for a long period underwater. The historian points out that the other large Russian vehicle is "Surrogat", which has a displacement of 40 tons and a length of about 17 meters, and its mission is to prepare operations for the Russian Navy against enemy submarines (previously, the Soviet fleet included special target boats). It can also solve communication and reconnaissance tasks, separately from the carrier submarine, ensuring its secrecy.