How battlecruiser hulls traded breadth for speed

Did a battlecruiser have a hull more like a battleship or a cruiser?

Its hull was generally longer and thinner than a battleship's, reflecting the greater emphasis on speed.

A battleship's fuller teardrop hull contrasts with the lengthened, thinner form typical of a battlecruiser. The difference was functional: extra length supported the speed required for scouting, commerce protection, and disengagement. Battlecruisers could therefore share capital-ship guns while remaining architecturally distinct from line-of-battle ships. The same distinction informs the later comparison between Scharnhorst, Renown, and Hood.