Silurian battlecruiser

Silurian battlecruisers were used by the Silurians and Sea Devils during their reign of the Earth in pre-historic times. They were built using organic material, not metal.

The battlecruisers were the equivalent of human submarines and were designed to dock with the Sea Devil colonies on the sea bed. The battlecruisers were also equipped with a particle suppressor as a defensive weapon.

One battlecruiser was that of Icthar and two other Silurians who, in 2084, used it to collect the Sea Devils of Elite Group One and then attack and invade Sea Base 4. (TV: Warriors of the Deep)