The Germans mined the Suez Canal, starting towards the end of January 1941

One of the things that the Germans could easily do that would cause the maximum disruption was to mine the Suez Canal. Starting in late January 1941, they started dropping mines from aircraft. After abortive minesweeping, the British guessed that they were dealing with both magnetic and acoustic ground mines. As they lacked a facility for sweeping acoustic mines, all that could be done was to interfere with minelaying with AA fire and to mark the location of dropped mines. The navy struggled to keep shipping moving through the canal.