Why did US cruisers not maneuver defensively while British battleships and cruisers zigzagged?
Short answerUS doctrine relied on destroyers to detect submarines, while the Royal Navy zigzagged habitually before detection and therefore disrupted Japanese long-range torpedo solutions.
NotesUS doctrine expected screening destroyers to detect and handle submarines, so cruisers could maintain a steady formation when no submarine warning existed. Many American cruisers also lacked the hydrophones or ASDIC carried by British counterparts. Royal Navy commanders zigzagged pre-emptively because the losses of Aboukir, Cressy, and Hogue had embedded a strong institutional fear of submarines. That precaution incidentally defeated a Japanese torpedo doctrine the British were not specifically anticipating, while US formations assumed the Japanese lacked such long-range weapons.