Submarines: C.1, C.2, C.3, C.4, C.5, C.6.
6th Flotilla. Chatham.
Depôt ships: Bonaventure and Hebe.
Submarines: C.7, C.8, C.9, C.10, C.12, C.13.
7th Flotilla. Chatham.
Depôt ships: Vulcan and Alecto.
Submarines: C.19, C.20, C.21, C.22, C.23, C.24, C.25, C.26, C.27, C.28, C.29, C.30.
8th Flotilla. Portsmouth.
Depôt ships: Maidstone and Adamant.
Submarines: D.1, D.2, D.3, D.4, D.5, D.6, D.7, D.8, E.1, E.2, E.3, E.4, E.5, E.6, E.7, E.8, E.9.