Force Z was more than a torpedo-protection failure

Did Prince of Wales have inadequate torpedo protection, or were Japanese aerial torpedoes overpowered?

Neither alone explains the loss; vulnerable hit locations, repeated attack, isolation, and failed communication over fighter cover were decisive.

No torpedo-defense system protects every opening where shafts and other machinery pass through the hull, and repeated attacks eventually found damaging locations. Force Z also operated without the fighter support it might have requested: the RAF discussed unavailable strike aircraft while the Navy needed air defense, leaving an available fighter squadron unused. The Japanese torpedoes were effective, but neither uniquely unstoppable nor proof that the King George V system was inherently worthless.