Posidon is a Russian underwater unmanned vehicle with a nuclear power plant, which is officially positioned as a strategic weapons of retaliatory strike. Its main feature is the ability to carry a nuclear warhead over virtually unlimited distance underwater, making it a fundamentally new class of armaments without a world analogue.

Key Characteristics

According to official statements and expert assessments, the parameters of the vehicle look as follows.

Development History

The existence of the vehicle first became known in 2015 from a leak on Russian state television. Officially, “Posidon” was presented by President Vladimir Putin in 2018 as part of the announcement of new strategic weapons.

The key stage of testing was October 2025, when, according to Putin, it was first possible not only to launch the vehicle from a submarine carrier but also to activate the nuclear power plant on which it worked for a certain period of time. In May 2026, Putin said that work on “Posidon” is at the final stage.

Role and Designation in Strategy

“Posidon” is considered a weapons of retaliatory strike. Its task is to guarantee the destruction of critically important coastal objects of the enemy (military bases, ports, cities) even if anti-ballistic missile defense (ABM) systems intercept ballistic missiles.

The key advantage over traditional carriers is the ability to bypass existing ABM systems. Missiles can be intercepted on their trajectory, while “Posidon” moves underwater, where modern countermeasures are ineffective. Moreover, the nuclear power plant gives it virtually unlimited range, allowing attacks on targets along any country's coastline.

Assessments and Skepticism