 From June 1915 she was listed as part of the Portsmouth Local Defence Flotilla.On 6 September 1916 she sighted a German submarine off Cape Barfleur, in the English Channel, forcing it to dive.On 18 January 1917 "Spiteful" was despatched from Portsmouth with three other destroyers to go to the aid of , another destroyer that had been disabled by an enemy torpedo while hunting German submarines in mid-Channel south-east of the Isle of Wight; "Ferret" was recovered to Portsmouth.