EPISODE: The Sea Devils: Episode Three
OVERALL EPISODE NUMBER: 314
STORY NUMBER: 062
TRANSMITTED: 11 March 1972
WRITER: Malcolm Hulke
DIRECTOR: Michael Briant
SCRIPT EDITOR: Terrance Dicks
PRODUCER: Barry Letts
FORMAT: DVD: Doctor Who - Beneath the Surface (The Silurians / The Sea Devils / Warriors of the Deep)
Episode Format: 525 video RSC
Trenchard interrupts the fight and has the Doctor arrested. Jo is apprehended leaving the prison but escapes. Captain Hart sends a submarine to the Sea Fort to investigate if anything is going on beneath the surface. The Master tells the Doctor that he intends to help the reptiles take over the Earth. Jo breaks back into the prison to find the Doctor, who distracts his guard allowing Jo to free him. Captain Hart enquires with Trenchard about the missing Doctor & Jo but he denies any knowledge. The submarine detects a signal and suddenly has it's power drained. Hart decides to contact UNIT about the Doctor's whereabouts. The submarine hits bottom and is boarded by the reptiles. The Doctor & Jo escape from the prison onto the beach where they find themselves trapped between a Minefield and the Sea Devil Reptile the Master is summoning from the sea.
The main thing I got from this episode was what a gullible fool Trenchard is. There's no hint that he's been hypnotised by the Master, he really believes the story revealed here that the Master will help him apprehend enemy agents and will do anything to help him including helping him break into a naval base, letting his prisoner roam free and imprisoning agents for an internationally recognised agency. I'd say he was Horatio Chinn II (Claws of Axos) but he's nowhere near as annoying as Chinn was. Just stupid.
We see the naval submarine in this episode represented by some stock Royal Navy training footage and a model kit, bought from Woolworths, with a propeller modified by the visual effects department to disguise it's origins. After this episode went out Barry Letts, the series producer, had a visit from Ministry of Defence officials concerned that their new top secret propeller design had been shown on tea time television. By chance visual effects had come up with something virtually identical to secret cutting edge military technology. The inside of the sub meanwhile bears a resemblance to the SkyDiver sub seen in UFO. I can't be 100% sure if it is the UFO set recycled as I'm not able to find a decent reference photo online but the series would have recently completed and other set elements from the show, notably a computer bank which we'll keep an eye out for, crop up regularly in later episodes of Doctor Who.
The submarine crew is packed with familiar faces: Commander Ridgeway is played by Donald Sumpter who was Enrico Casali in The Wheel in Space while his number 2, Lt. Commander Mitchell, is played by David Griffin who gained fame as Sqdn-Ldr Clive Dempster DFC in Hi-de-Hi! & Emmet Hawksworth in Keeping Up Appearances. Christopher Wray, here as Ldg. Seaman Lovell, was PC Groom in The Dæmons while Stanley McGeagh, Castle Guard Drew was another actor who was in director Michael Bryant's previous production Colony in Space where he played Allen.