Mine warfare was a First World War lesson that Germany could have exploited more fully. Long-range submarines laying mines outside American harbours might have imposed shipping losses, clearance work, delays, and pressure on scarce escort forces. Britain entered the war better prepared because the Third Sea Lord from 1933 to 1939 had analyzed how blocked harbours fractured convoy schedules and multiplied escort problems. That work helped drive a threefold expansion of mine-clearing capacity. Mines mattered as much for the logistical and operational disruption they caused as for the ships they sank.
Chapter · 15:41-20:37
The underused threat of submarine minelaying
German minelaying submarines had inflicted heavy shipping losses in the First World War, yet the Second World War U-boat campaign emphasized torpedoes and guns over a wider mining effort.