The Sea Devils was the third serial of season 9 of Doctor Who. It marked the first appearance of the Sea Devils and the reappearance of the Master, now plotting to escape confinement from a maximum security prison.

Barry Letts and Terrance Dicks had decided they wanted a sea-based story and asked Malcolm Hulke to write it. Rather than merely bringing back the Silurians, Hulke invented an aquatic version called the Sea Silurians. Unlike their earlier counterparts, these "Sea Devils" were given clothing, designed by Maggie Fletcher.

To answer the insistence by fans that the Silurian era could not have spawned man-sized life, Hulke introduced a line in which the Doctor says they should correctly be called Eocenes. However, this period was still well in advance of humanoid life.

After the Master appeared in all five stories of season 8, Letts decided to restrict him to a few appearances each year. This story joins him where The Dæmons left off, in prison. The dialogue implies he and the Doctor were once friends.

Letts had secured the involvement of the Royal Air Force for The Mind of Evil and decided to try to do the same with the Royal Navy. He found the Ministry of Defence eager to take part. Many of the extras that played the navy personnel were active duty sailors. Shortly after broadcast, the BBC was visited by officials from the MOD who believed a top-secret submarine had been used in the show. It was in fact a model, adapted to show the features they were secretly testing.

Expensive location filming left The Sea Devils with a budgeting problem. Director Michael Briant's solution was to not hire regular incidental music composer, Dudley Simpson, and have the score created by the BBC Radiophonic Workshop. Malcolm Clarke's electronic score was one of the serial's signatures.[1] Its significance was attested to by its inclusion in 2013's Doctor Who at the Proms, where it was one of five pieces of incidental music performed as representative of the show's original run.

This story saw the only use of the catchphrase "reverse the polarity of the neutron flow" during the Pertwee era. The phrase became associated with the Third Doctor, so he used it again in The Five Doctors some eleven years later, although between seasons 7 and 11 Pertwee did use a shortened version of the phrase, "reverse the polarity", several times.

Like many of Hulke's stories, it included a moral dimension. The Sea Devils are caught between the Master, the Doctor and the humans. Ultimately, they are betrayed by all three; like their land-based cousins, it is the humans who hurt them the most.

Synopsis Edit

The Doctor and Jo visit the Master in his high-security prison on an island off the south coast of England. The governor, Colonel Trenchard, says ships have been disappearing mysteriously at sea. The Doctor discovers that Trenchard and the Master are in league to contact the Sea Devils, a race of reptiles in hibernation in a base beneath the sea, who have been awoken by recent work on a nearby sea fort. The Master intends to use his new allies to help him conquer the world.

Plot Edit

Episode one Edit

Visiting hours

The Doctor and Jo visit the Master in his cell.

The Third Doctor and Jo visit the Master, now a captive on a small island prison after being captured by UNIT.

The Master is being held indefinitely and is the only prisoner. He is watched by CCTV, and the island is patrolled by armed guards — trained to resist the Master's hypnotic powers — and even protected by minefields. He claims to have reformed, but refuses to reveal the location of his TARDIS. As they depart, the old-school, patriotic governor, Colonel Trenchard, tells them that some ships have been disappearing mysteriously. Shortly afterwards, he visits the Master, and it becomes clear that they are in league.

The Doctor cannot resist investigating, so they visit the nearby naval base, HMS Seaspite, run by the efficient Captain John Hart; despite the Doctor's eccentric behaviour — he claims to have known Nelson personally — an alliance forms. The Doctor states that that the linear scorch pattern was caused by a concentrated beam of heat from under the sea. Hart is in charge of the adaptation of the sea fort to a sonar testing station. The Doctor and Jo make their way to the sea fort. While investigating the fort, their boat explodes. They then find the body of one of the maintenance crewman, Hickman. Jo then hears something shuffling towards them.

Episode two Edit

Sea Devil says hi

A Sea Devil is discovered by the Doctor.

It is the second crewman, Clark, who is now half-mad. He is ranting about "Sea Devils". The Doctor and Jo try to calm him down. They find that the radio was ripped out. The Doctor decides to go get a transistor radio in order to turn it into a transmitter. On his way, he encounters a hostile reptilian Sea Devil, who fires at him. When it tries to break in, it is injured and flees. Shortly afterwards, the Doctor finishes his transmitter, and they are rescued.

Captain Hart decides to find them after they apparently disappear. The Doctor and Jo attempt to get Hart to tell a higher authority. His assistant gets a call from someone ranting about Sea Devils. The Master comes to HMS Seaspite to steal some equipment, posing as an officer but is caught in the act of robbing the stores by a petty officer but the Master knocks the man unconscious. In the meantime, Colonel Trenchard is providing a distraction by visiting Hart however Jo sees the Master leaving. The alarm is raised but the Master and Trenchard have already escaped.

The Doctor and Jo confront Trenchard, and he tries to dissuade them by showing that the Master is in his cell. The Master knocks out a guard and grabs his knife. Trenchard then gets the Doctor to go and see the Master, who attempts to kill him, first with a gun and then with a sword. The Doctor and the Master engage in a sword fight. The Master then throws a dagger at the back of the Doctor's head....

Episode three Edit

The Master and Trenchard

The Master working in his cell.

The Master misses, and the Doctor is unharmed. Trenchard enters and decides to lock the Doctor in the prison and attempts to capture Jo. The Master tells him that he intends to use the reptiles as an army to conquer the planet.

It is revealed that the reason Trenchard is helping the Master is because he believes they are fighting enemy agents. Meanwhile, Jo comes and frees the Doctor. The Master and Trenchard give chase, and the Master uses the machine to summon a Sea Devil from the ocean. The Doctor and Jo are trapped between the Sea Devil, the Master, and a minefield.

Episode four Edit

Sea Devil strike

The Sea Devils attack the submarine.

The Doctor is forced to employ his sonic screwdriver to repel the Sea Devils by exploding mines on the beach. While the Doctor and Jo navigate through a mine field, a Sea Devil attacks a submarine Hart arranged to be sent to investigate the sinking of the ships. The Doctor and Jo flee to HMS Seaspite, where Hart tells them another naval submarine has disappeared.

Meanwhile, the Master returns to his cell to begin work on a new device. He activates it, and it calls the Sea Devils to him. They attack the prison, killing the guards. A battle for the prison rages. Trenchard, who believed he was aiding his country against enemy agents, is killed.

Sea Devils around diving bell

The Sea Devils surround the diving bell

The Reclaim heads out to investigate a section of seabed. The Doctor goes down in a diving bell. When they offer to pull him up, he refuses; however, his communication system fails, and Captain Hart orders the crew to pull up the diving bell. When it reaches the ship, it is empty...

Episode five Edit


The Master and Sea Devils converse.

The Sea Devils take the Doctor to their leader. The Doctor enters the Sea Devils' base and tries to encourage peaceful negotiation, recalling how he had failed to broker an agreement between mankind and the Silurians. The Master arrives to incite matters by trying to provoke war.

Walker, the parliamentary private secretary, arrives to "solve" the sinking ship problem by dropping depth charges. Meanwhile, the Doctor has gained the upper side of the argument — the Sea Devils agree to consider diplomatic relations. The depth charges disrupt the negotiations. The Master convinces the Sea Devils to take the Doctor away and kill him. He also convinces them to attack one of the naval bases.

Navy ship weapons firing - Sea Devils

Navy firing on the Sea Devil's base.

In the confusion caused by the depth charges, the Doctor escapes, gets a Silurian gun from a fallen Sea Devil, and uses it to melt a door and rescue two of the submarine crew. They rescue the others still in the submarine. The leader of the submarine crew kills one of the Sea Devils with the gun that the Doctor picked up; it is implied[by whom?] that others were killed on the upper level of the sub. They try to leave, but the Sea Devils hold them back with a force field. They fire torpedoes to provide thrust and escape.

The Doctor confronts Walker about his depth charges, which have just made the Sea Devils angry. The Sea Devils rise and attack the HMS Seaspite. The Doctor attempts to go to negotiate again. As they round a corner, a Sea Devil appears and raises its gun at them...

Episode six Edit

The Doctor fights the Sea Devil off with Venusian karate, but another captures him. The rest of the Sea Devils capture the rest of the people at the base. Jo, Captain Hart, and Mr Walker are held in one of the offices at the base. The Master tells the Doctor that he needs help to complete his machine so he can revive the colonies all over the world.

Meanwhile, Jo escapes through a ventilation shaft. She reaches the Doctor, and he tells her that he will deal with the guards; he sends her back to retrieve Captain Hart and Mr Walker. The Doctor makes the machine emit a shrill noise, which puts the Sea Devils in agony. Captain Hart escapes with Jo, but Mr Walker retreats into the office and shuts himself back in when faced with a Sea Devil, even though the creature is incapacitated by the noise from the machine. The Master shuts off the machine, and the Doctor apologises for the "mistake" that caused the noise. The Sea Devils, the Doctor, and the Master head back to the Sea Devil base.

Resigned Three

The Doctor looks on resignedly as the Master gets away once again.

The prisoners retake the base. A soldier arrives, and the Doctor orders him to keep watch over the Master, but the Master hypnotises him and escapes. The Doctor chases after the Master, and they reach the base, where multiple Sea Devils capture them. Meanwhile, Walker orders a nuclear strike. The Doctor sabotages the machine, and the two Time Lords are imprisoned. The Doctor reveals that he reversed the polarity of neutron flow, which will cause a massive explosion. The Time Lords escape by using the Doctor's sonic screwdriver to get out of their cell; they find diving suits and exit the base. They rise to the surface and are rescued just before the base explodes, and the Sea Devils are destroyed.

The rescuers call an ambulance for the Master, who seems to be very ill; however, when the ambulance arrives, they realise that the man is not really the Master, but someone else wearing a disguise — the Master has hypnotised him and forced him to impersonate the Master. They realise that the Master is escaping in a hovercraft. Too late to do anything to stop him, all they can do is bitterly watch their foe taunt them as he scurries away to freedom.

Cast Edit

Uncredited cast Edit

Crew Edit

Uncredited crew Edit

References Edit

Foods and beverages Edit

  • The Doctor consumes several sandwiches at the naval base.
  • Hickman is seen drinking Old Oak Light Ale.
  • Walker continually asks Officer Blythe to bring him food and tea. He also eats smoked salmon.

Species Edit

  • The Silurians had emerged from some caves in Derbyshire.

The Doctor Edit

Vehicles Edit

Story notes Edit

  • This story had the working title The Sea Silurians.
  • This is one of two television stories where the Third Doctor utters the full line, "I reversed the polarity of the neutron flow" (in episode six). The other is in The Five Doctors.
  • The scene involving the Master watching The Clangers on television was a last-minute addition, added because episode one was running ninety seconds short.
  • This serial's director, Michael Briant, provided the voice of the radio DJ in episode two.
  • This is the last story to feature the Third Doctor wearing his original outfit in his run. It wasn't seen again until The Day of the Doctor.
  • This is the last story that HAVOC worked on.
  • Originally, episode one was to include the Doctor water-skiing, which was to be used as the excuse for Jo and him being late to the Master's prison. Increasingly inclement weather made the shoot impossible.
  • The Radio Times programme listing for the 90-minute compilation repeat of the story on Wednesday 27 December 1972, billed as Dr Who and the Sea Devils, was accompanied by a black and white illustration by Frank Bellamy depicting a Sea Devil, the Master and the Doctor, along with a comic strip-style caption "THE WHOLE PLACE WILL GO UP IN APPROXIMATELY TEN MINUTES / ENJOY YOUR REVENGE!", with the accompanying caption "Time-warp time — the Doc takes on the Master and the Sea Devils: 3.5". The compilation also received an unscheduled showing at 11:15 a.m. on Monday 27 May 1974 as a replacement for the Yorkshire -v- Lancashire cricket match, the planned coverage of which was disrupted by industrial action.
  • Reproductions of actual script pages, accompanied by extensive production notes about this serial, are featured in the book The Making of Doctor Who.
The Sea Devils credits - Royal Navy

Royal Navy thanked in The Sea Devils credits.

  • This is one of only eleven televised stories in the history of Doctor Who not to feature the TARDIS at all, along with Mission to the Unknown, Doctor Who and the Silurians, The Mind of Evil, The Dæmons, The Sontaran Experiment, Genesis of the Daleks, Midnight, The Lie of the Land, The Woman Who Fell to Earth and Ascension of the Cybermen.
  • After the show aired, MI5 came to the studio asking how they came up with the nuclear submarine model. The director and the visual effects designer explained that they simply used an off-the-shelf model kit, but replaced the propeller with a vacuum cleaner part because the model’s propeller didn’t look seaworthy. By sheer happenstance, the vacuum cleaner part had the exact same number of blades as the real nuclear submarine's propeller, meaning they accidentally guessed classified information that revealed the sonar signal that identified British nuclear submarines.
  • Director Michael E. Briant admitted that Malcolm Clarke's choice of music was a mistake. Clark himself admitted that he never cracked the problem of what Barry Letts liked and if he could have modified the work.
  • During filming, stunt performer Stuart Fell nearly drowned when he fell over in the surf and his rubber monster costume filled with water.
  • The sea fort setting was a late change to the scripts: Malcolm Hulke had originally written this material for an oil rig, but Michael E. Briant was unable to obtain permission to film on one.
  • The Doctor's line about the Silurians actually being called Eocenes was added by Malcolm Hulke after fans pointed out that the Silurian era could not have produced man-sized life.
  • Jon Pertwee injured his ribs during recording when he dived forward and fell on the sonic screwdriver prop, which was stowed in his breast pocket.
  • The script originally had a speedboat chase, but Jon Pertwee suggested jet skis.
  • Nicholas Courtney was on holiday during the making of this story, hence the absence of UNIT and the Brigadier.
  • Michael E. Briant recalled that there was a huge discussion on location about how the Sea Devils couldn't be naked, so costume designer Maggie Fletcher had to rush out and buy five hundred yards of fishing net.
  • The Sea Devils' masks were based on turtles.
  • In the first episode, the script called for Jo Grant and the Doctor to climb up a ladder to get into a sea fortress. The ladder proved too slippery for Katy Manning, so stuntman Stuart Fell did the shot dressed as Grant.
  • According to Katy Manning, nearly the entire production came down with seasickness during production. Jon Pertwee was the exception, due to his experience as a sailor.
  • Katy Manning recalled that she and Jon Pertwee did the abseiling stunt themselves, despite her having never done it before. She promptly took the skin off her hands as a result.

Ratings Edit

  • Episode one - 6.4 million viewers
  • Episode two - 9.7 million viewers
  • Episode three - 8.3 million viewers
  • Episode four - 7.8 million viewers
  • Episode five - 8.3 million viewers
  • Episode six - 8.5 million viewers

Myths Edit

  • Roger Delgado was afraid of the water, as he couldn't swim, and it took great courage for him to film the scene in which the Master and the Doctor are rescued from the sea by the Navy. (This was frequently recalled by Jon Pertwee in later interviews; but according to Delgado's widow, Kismet, it is untrue: Delgado was actually worried about getting his costume wet, as there was no spare available. Nonetheless, Delgado's fear of water is also recalled during the DVD commentary of The Sea Devils by Barry Letts and Terrance Dicks. Michael Briant also recalls this in the documentary Hello Sailor! Indeed, Delgado looks very uncomfortable during his scenes in the water in the finished programme.)

Filming locations Edit

  • The exterior of the Master's prison was in fact Norris Castle, East Cowes, Isle of Wight.
  • The sea fort is No Man's Land Fort, which is also referred to as No Man's Fort.
    • It is a sea fort in the Solent, near Portsmouth, England.
    • It is one of the Palmerston Forts built between 1867 and 1880 after the recommendations of the 1859 Royal Commission. It is 200 feet in diameter, and lies 1.4 miles off the coast of the Isle of Wight. Built in anticipation of a feared French invasion which never came to pass, it was abandoned at the time of the story's filming.
    • In July 2007, the fort came up for sale after the company owning a proposed hotel idea collapsed and its owner was jailed. In April 2015, the fort finally opened as a hotel, with prices upward of £400 a night.
  • Fraser Gunnery Range, HMS St George, Portsmouth
  • Royal Navy ship HMS Reclaim
  • No Man's Land Sea Fort, Solent
  • Whitecliff Bay, Isle of Wight
  • Bembridge Harbour, Isle of Wight
  • Norris Castle, East Cowes, Isle of Wight
  • Red Cliff, Sandown, Isle of Wight
  • Bembridge Sailing Club, Bembridge, Isle of Wight
  • Priory Bay, Isle of Wight
  • BBC Television Centre (Studio 8), Shepherd's Bush, London
  • The beach in front of the naval base (Fraser Gunnery Range, HMS St George, Portsmouth) is a nudist beach, as are the sand dune parts of Climping Beach in Littlehampton West Sussex, which featured in The Enemy Of The World.

Production errors Edit

If you'd like to talk about narrative problems with this story — like plot holes and things that seem to contradict other stories — please go to this episode's discontinuity discussion.
  • The clock in the Master's prison cell runs backwards.
  • The Master knocks out a prison guard who enters his cell in episode two. The guard then subsequently disappears, never to be seen again.
  • When the Doctor first takes out the sonic screwdriver in the minefield, a microphone can be seen at the bottom left of the shot.

Continuity Edit

Home video and audio releases Edit

Editing for both the VHS and DVD releases was completed by the Doctor Who Restoration Team.

DVD releases Edit

This story was released on DVD as part of the Beneath the Surface collection along with Doctor Who and the Silurians and Warriors of the Deep.

Beneath the Surface Edit

Digital releases Edit

This story is available:

  • for streaming through BritBox (US) as part of Season 9 of Classic Doctor Who.

VHS releases Edit

This story was released on video in episodic format.

Audio releases Edit

A CD of the original television soundtrack was released in January 2008, with linking narration by Katy Manning. It was also included in the Monsters on Earth box set along with Doctor Who and the Silurians and Warriors of the Deep.

Footnotes Edit

External links Edit

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