If Royal Oak became a Vanguard-class battleship in 1939, would she survive the U-boat attack at Scapa Flow?
Short answerPossibly: she would have better protection and might remain afloat long enough for recovery. She might also be deployed elsewhere, so the historical attack need not recur.
NotesVanguard's protection and internal systems would give a transformed Royal Oak better prospects after torpedo hits, but survival is not assured. Remaining afloat longer might allow the damaged ship to be moved somewhere repairable. The counterfactual also changes deployment: a modern, fast battleship would be more likely to receive an active assignment elsewhere. Royal Oak's historical anti-aircraft role at Scapa Flow therefore cannot simply be carried over to the replacement ship. Avoiding that station could matter more than the result of the same attack against a stronger hull.