Sea Base 4 was a sea base in the ocean on planet Earth. It was active during 2084; part of Sea Base Command, it had several weapons systems including energy tracers.
During 2084 Sea Base 4 was involved in a conflict with the Sea Devils and the Silurians. All of the staff died in the attack, however the Sea Devils and Silurians were killed following a release of Hexachromite gas by [[Fifth Doctor|the Doctor. (DW: Warriors of the Deep)
Staff
