Russia has tested a nuclear-capable drone sub that could pose a strategic threat to US ports

[Penguin]

Thanks, I am aware of that, it will be tested and if it works _due to some very heavy parameters.. like avoiding other ships for instance_, that it might be considered//still this new Russian drone/sub dives at 1000 m or a bit more than 3000 ft !!!

Diving depth is not going to matter much once approaching the target coast, e.g. here near New Jersey/ Delaware/Maryland/Virginia. Besides, I doubt it can actually enter coastal areas where e.g the ports Norfolk and Baltimore are located. Consequently, to take out these areas, it is a weapon that is necessarily very crude and imprecise. In fact, This weapon is designed to create a tsunami wave up to 500m tall that will radioactively contaminate a wide area on an enemy coasts with cobalt-60.

Compared to a 100mt blast over Boston area: thermal radius 77km. (which is about the distance comparable to 50mi offshore to the shore above).

Incidentally, the weapon would take 40 hours to get to the coast, not all of which is at great depth.