On the afternoon of 24 April, the battlecruiser struck a mine, and on detecting and deciphering German radio signals referring to the mining, the British Admiralty ordered six submarines accompanied by "Melampus" to intercept the German forces. Later that night, the destroyers and cruisers of the Harwich Force were ordered out, to find the German force, and to induce the Germans to chase the British force into the path of the waiting British submarines. After the Germans bombarded Lowestoft and Yarmouth, "Melampus" received orders to her submarines to deploy in a patrol line to have the best change of intercepting the German ships on their return journey. "Melampus" sighted German ships when relaying the new orders to her submarines, and after completing passing on the orders, withdrew at high speed from the German ships. None of the British submarines managed to get close enough to the German ships to engage the Germans. One of the British submarines, , was torpedoed and sunk by the German submarine . In September 1916, the 8th Submarine Flotilla was split in two, with most of the Flotilla, including "Melampus", joining the 9th Submarine Flotilla, still part of the Harwich Force. On 16 April 1917, "Melampus" was exercising with the submarines and off Harwich, when "C16" crossed in front of "Melampus" at periscope depth. "Melampus" sighted "C16"s periscope, and attempted to take evasive action, but it was too late and the destroyer and submarine collided, sinking "C16". Attempts by "C16"s crew to escape were unsuccessful, with all drowning. "Melampus" was cleared of all blame in the resulting enquiry. "Melampus" was credited with the sinking of the submarine on 22 October 1917, with Prize Money awarded to the destroyer's crew, but "UC-16" had probably been sunk in a British minefield  off Zeebrugge earlier in the month. "Melampus" remained part of the 9th Submarine Flotilla at Harwich at the end of the war. "Melampus" was still part of the 9th Flotilla in February 1919, but by March had left the Flotilla, and moved to Devonport. She was sold for scrap on 22 September 1921 and broken up in Germany.