In February 1914, the Tribals, whose range was too short for effective open sea operations, were sent to Dover, forming the 6th Destroyer Flotilla. On the outbreak of the First World War, the 6th Flotilla formed the basis of the Dover Patrol, with which the Tribal class, including "Afridi", served for the duration of the war. Early in the war, the main means of detecting submerged submarines was the indicator net, in which a submarine would get caught up in the net, with movement of an attached buoy indicating the location of the submarine. On 20 February 1915, the destroyer spotted a disturbance in indicator nets in the Dover Straits, and signalled to "Afridi" to deploy her explosive anti-submarine sweep, but no submarine was found. On 6 April 1915, the drifter "Hyacinth" spotted a periscope of the German submarine and called up "Afridi", which was nearby. While the submarine carried away a section of the netting, the indicator buoys did not deploy, so "U-33" was able to escape unscathed.