Creeping Attack (Civ6)/Civilopedia

During the early stage of the anti-submarine war, during the final run of a convoy escort to drop stern-mounted depth charges on a skulking U-boat contact was lost by the active sound detection system (ASDIC) ... giving the German sub the chance to change depth or direction at the last minute. To counter this, the Royal Navy's 36 Escort Group devised the "Creeping Attack." Using two ships, one stationary to maintain contact and one to close on the target, the latter releasing its depth charges on a signal from the first. Although the tactic required patience, and took extra time and ships, it proved effective. The arrival of more sophisticated ASDIC, along with forward-throwing Hedgehog and Squid depth charges, made the tactic obsolete – although the British continued to use it to war's end.