To an Ohio Class.
That's right, another stupid challenge that someone's probably posted before. This one focuses on a simpler set of requirements:
1. Submarine, baby.
2. Ballistic Missile capable.
3. Nuclear (not Fusion) powered, possibly with a fuel-cell backup for silent running or to reduce wear and tear (and radiation issues).
Like to sees:
Command and Control hardware of some kind, preferably more advanced than the 21st century equivalent (per Battletech's universe).
Somewhat better dive depth/crush depth if you can find a way to get it.
Backstory being that these were literally based on 20th and 21st century designs upgraded with better materials and given 'soft upgrades' to the technology to serve as a mobile anti-dropship/jumpship ADA platform with some secondary role as a mobile command post able to hide in water too deep to hit with naval autocannons/lasers/ppc's/non-depth charge missiles.