What chance would an all-U-boat German navy have had against the Royal Navy if it built no heavy cruisers or larger warships?
Short answerIt would intensify the submarine war but also let Britain focus production and deployment on anti-submarine forces while moving capital ships and carriers to other theaters.
NotesA German decision to build only submarines would likely have prompted earlier Royal Navy sloop, corvette, and escort expansion. Without major surface raiders, Britain would not need to disperse battleships and cruisers across Atlantic searches, and operations such as Norway might become less viable for Germany. Freed carriers and capital ships could strengthen Mediterranean and Far East forces, showing why several different threat types imposed more strain than a larger version of only one. Concentrating German resources in one threat axis would also let British industry and training concentrate on one family of countermeasures.