The limits of submarines as visible deterrence

Can small and large submarines be understood as equivalents of coastal battleships and battleships?

No: conventional submarines lack the visible presence role of surface capital ships, though hidden SSBNs serve a different deterrent purpose.

The analogy between coastal and larger submarines does not map cleanly onto battleships. Surface capital ships can visibly signal presence, reassure allies, and warn opponents before combat begins. Conventional attack submarines derive much of their value from remaining unseen, making them potent warfighting tools but awkward instruments for a visible presence mission. Ballistic-missile submarines are different because hidden survivability is central to nuclear deterrence. This separates conventional signalling from the retaliatory logic of an SSBN force.