Poseidon (Nuclear Underwater Drone)

[BHAN85]

https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_System

The Poseidon (Russian: Посейдон, "Poseidon", NATO reporting name Kanyon), previously known by Russian codename Status-6 (Russian: Статус-6), is an autonomous, nuclear-powered, and nuclear-armed unmanned underwater vehicle under development by Rubin Design Bureau, capable of delivering both conventional and nuclear payloads.

The Poseidon is one of the six new Russian strategic weapons announced by Russian President Vladimir Putin on 1 March 2018

https://sputniknews.com/military/20...gorod-sub-to-last-until-end-of-2021---source/ (May 26th 2020)

 

[BHAN85]

https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_System

Stealth technology

The development includes also use of stealth technology, to elude acoustic tracking devices. Poseidon uses a silent running strategy like other submarines. Its main stealth feature is its very low speed before it reaches the target area. Its high-speed mode activates upon reaching a short finish range (2–3 kilometers), when the probability of detection of the drone is considerably higher. It could travel for weeks toward enemy port cities, reaching high-speed only in the final stage

Russian designers estimated the radius of detection of the drone will be about 2–3 km (1.2–1.9 mi) for 55 km/h (34 mph).[30] A second important stealth feature of the drone is the special design of the pump-jet for clearance of the drone's acoustic signature to imitate the noise of civil ships.

I think this is particularly interesting, it seems Russians dont trust in the invisibility of the ocean anymore.
Make a Sosus network today is very cheaper than decades ago, and who know what USA and China has made in that field in the last years.