
| Commanding Officers | |||
| R.C Halaham | 1909 | ||
| M.E Nasmith | 1911 | ||
| A.M.Willoughby | 1911 | ||
| Lt. V.E Ward | 1912 | ||
| Lt D.M. Hervey-Macleay | 1916 | ||
| List not complete | |||
Laid down on 11 March 1907 and launched on 10 October 1908 by Miss Giffard, daughter of the Admiral Superintendent, Vice Admiral George A.Giffard. CMG.
At the outbreak of WW1, C18 was based at Dover and under the command of Lt. V. E. Ward.
She operated from Dover for most of the war but in 1918 she transferred to the 6th Flotilla at Portsmouth.
C18 was sold to scrap in Sunderland on 26 May 1921.
The image shows C18 alongside the Depot ship Arrogant at Dover in 1917
The history of this submarine is still being researched.