How did the Royal Navy fight at night before radar?
Short answerIt built on Harwich Force and motor torpedo boat experience, improved weak low-light optics, and kept practising visual night fighting until radar could reinforce an existing method.
NotesHarwich Force and motor torpedo boat operations supplied early experience, while World War I revealed that the Royal Navy's low-light optics performed worse than expected. The Navy kept investing in improvements and continued to exercise the unsolved problem instead of assuming that one sensor had removed it. Excessive confidence in ASDIC provides a contrasting anti-submarine example of how reliance on one system could narrow thinking. Familiarity with visual uncertainty later allowed radar to reinforce existing tactical practice without displacing judgement.