Mürwik built U-boat officers over four years

Officer candidates at Mürwik studied seamanship, navigation, tactics, strategy, gunnery, and naval history during an initial ten-month course. Their preparation included a three-month sailing-ship voyage and a longer spell aboard a modern warship, sometimes lasting fourteen months, to put theory into practice. Such voyages carried risks: a three-masted predecessor to the later sailing training ship was lost in the Baltic in summer 1932 with 69 lives, about half of them officer cadets. Returning candidates faced assessment by their peers before promotion and further instruction. The later stages comprised seven more months at the academy, five months of specialist training, and six months aboard an active warship to develop leadership experience. By the time a candidate began service as a U-boat officer, the process could have occupied four years. The four-year preparation made trained leaders slow to replace when losses disrupted expansion.