How different were Royal Navy and German naval mines during the two world wars?
Short answerTheir First World War contact mines were broadly similar, but Second World War mine warfare expanded into magnetic, acoustic, and influence weapons.
NotesBritish and German First World War mines are judged broadly similar in their basic design. The familiar contact mine could be spherical or barrel-shaped, with projecting Hertz horns. Second World War mine warfare included magnetic, acoustic, and other influence types. Those developments widened the means by which a mine could detect a passing ship.