Yorck's loss and the double edge of mine warfare

Yorck was lost in November 1914, generally attributed to German mines. One remote possibility is that a drifting British mine was responsible, though this explanation is considered unlikely. A brief American example adds that intercoastal waterways are difficult for submarines to mine directly and might require small-boat crews or another delivery system. The uncertainty over Yorck matters less than the operational lesson that follows. A defensive minefield must leave a usable channel for friendly movement, and that channel requires regular sweeping because even its own mines can shift. An enemy able to add mines to the expected safe route can therefore turn a protective barrier into a hazard for the fleet it was meant to defend.