Cruiser submarines traded agility for range and payload

Is a modern nuclear submarine effectively the same thing as an interwar cruiser submarine?

Not quite: the cruiser-submarine idea depended on exceptional endurance and reload capacity, while its large hull and added roles imposed serious diving and payload tradeoffs.

An interwar cruiser submarine differs from a modern nuclear attack boat because the older concept emphasized endurance and a much larger reload supply rather than propulsion alone. A bigger hull can carry more fuel, torpedoes, stores, and even a reconnaissance aircraft, making distant commerce raiding more plausible. The same size increases diving time and creates pressure to sacrifice one capability to make room for another. Removing torpedoes for aircraft, command spaces, or cargo can leave a long-range submarine less able to perform the basic attack mission. The concept therefore begins with a real operational need but accumulates compromises as designers try to make one boat scout, raid, command, and fight on the surface.