The Sea Devils is the third serial of the ninth season of the long-running British science fiction television series Doctor Who, which was first broadcast in six weekly parts on BBC1 from 26 February to 1 April 1972.
The serial is notable as the first appearance of the Sea Devils and features extensive location filming in cooperation with the Royal Navy, as well as an experimental electronic score by Malcolm Clarke.
The Doctor discovers that the Master, with the misguided aid of his ostensible jailor Colonel Trenchard, is stealing electrical equipment from a naval research establishment on the island to build a machine that will control the so-called Sea Devils, intending to use them as an army through which to conquer the world.
The Doctor and Jo once again flee to the naval base where the commanding officer, Captain Hart, tells them a submarine has disappeared.
The Doctor offers to broker peaceful negotiations between the sea-creatures and the humans, recalling how he failed in his earlier attempt with the Silurians, to whom the Sea Devils appear to be related.
Matters are left unresolved in the wake of an attack by depth charges ordered by Robert Walker, a politician who has arrived to take control of the situation and intent on repeating UNIT's actions against the Silurians, namely blowing them up, but this time with a nuclear weapon.
The attack is opposed by Jo, but does provide the Doctor with cover as he flees to the naval base, where he persuades Walker to allow him another, final attempt at negotiation.
The story was edited and condensed into a single omnibus episode, broadcast on BBC1 at 3:05 pm on 27 December 1972,[9] reaching 8.7 million viewers.
[10] A full repeat of all six episodes was shown on BBC2 from 6 March to 10 April 1992, 20 years after the original broadcast, with ratings of 3.12, 3.55, 2.96, 3.37, 3.10 & 3.04 million viewers, respectively.
[13] Paul Cornell, Martin Day and Keith Topping gave the serial a favourable review in The Discontinuity Guide (1995), calling it "a good Malcolm Hulke script", with a "pedestrian" pace that still allowed for some suspense.
[14] In The Television Companion (1998), David J. Howe and Stephen James Walker described the story as "a colourful adventure yarn" with quality direction and high production values.
[19] A novelisation of this serial, written by Malcolm Hulke, was published by Target Books in October 1974 and was originally to be titled The Sea Monsters.
There are, as usual with Hulke, many added sections—including an ironic death for Trenchard as he makes a last stand against the Sea Devils and forgets to take the safety catch off his pistol.
The story's original soundtrack was released on CD as part of the 'Monsters on Earth' tin set along with Doctor Who and the Silurians and Warriors of the Deep in October 2006 and linking narration was provided by Katy Manning.
The Sea Devils was released on DVD as part of a boxed set called Beneath the Surface with Doctor Who and the Silurians and Warriors of the Deep on 14 January 2008.