 Pari gbolohun ti o tẹle: S18 jẹ ọmọ ẹgbẹ ti 13th idaji-flotilla ti 7th Flotilla, apakan ti Awọn ọkọ oju omi Okun Okun giga ti Jẹmánì, ni ibesile ti Ogun Agbaye akọkọ ni Oṣu Kẹjọ ọdun 1914. Awọn 7th Torpedo Boat Flotilla ṣe atilẹyin awọn Raid on Yarmouth on 3 November 1914 ati awọn : Ìkọlù sí Scarborough, Hartlepool àti Whitby ní ọjọ kẹrìndínlógún oṣù kejìlá ọdún 1914. Awọn flotilla tesiwaju lati se atilẹyin fun awọn High Seas Fleet ni 1915, sortie sinu awọn German Bight pẹlu awọn 5th ati 9th Flotilla on 1920 January ati escorting a sortie ti awọn fleet ká battleships to kuro Terschelling on 2930 March. S18, gẹgẹ bí apá kan ti ẹka ọkọ òkun 7th Flotilla, jẹ apá kan ti Ẹka Ọkọ Òkun Òkè nígbà tí ó rìnrìn àjò láti bo Ìkọlù Lowestoft ní 24-25 April 1916. 