By 1917 the German defences on the Flanders coast included , a heavy artillery battery at Knocke, east of the Bruges Canal, of four 12in guns, with a range of 41000yd and the battery of four 11in guns, with a range of 35000yd, west of Ostend.
The cruisers involved in the blockade, including were equipped in Chatham, by over for the special fitting out and stripping out (in the case of the ships to be sunk) of unnecessary equipment, including their masts.