Would a broken keel make the battleship uniquely vulnerable?

Would the danger of an attack breaking the ship's keel be a decisive weakness?

No more than for any other ship; the design must reduce the chance of a hit through a layered uncrewed ASW screen and retain enough structural protection and redundancy to survive damage when possible.

A broken keel is fatal to any ship, so underwater protection becomes a problem of avoiding and absorbing attacks rather than a unique reason to reject a battleship. HMS Belfast survived severe mine damage and was rebuilt, while modern defenses can push the submarine threat farther from the hull. Uncrewed surface vessels with towed arrays could alternate sprint-and-drift or dash-and-sneak patterns on both sides and ahead of the capital ship, maintaining continuous passive coverage. Helicopters, dipping-sonar aircraft, and sonobuoys would add more search layers, while active sonar could be used when revealing the formation's position is acceptable. Older capital ships carried their own boats and even Victorian third-class torpedo boats, so organic small craft are an evolving form of self-protection rather than a wholly new principle. The large hull could also carry manufacturing equipment for simple expendables such as sonobuoys, extending the screen's endurance. This is a self-escort concept based on distributed detection, not a claim that armor makes torpedoes irrelevant.