Last updated 24 March 2024


Episode Six

Series Episode Number: 317

World Premiere: Sat 1 Apr 1972 - 5:51pm BST [BBC One] (United Kingdom)
First Broadcast: Mon 24 Nov 1975 - 6:30pm CST [WTTW 11 Chicago]
Running Time: 25 minutes 24 seconds

8.50 Million (UK)


Chart Position: 47 () (UK)

Recorded on Tue 14 Dec 1971 in TC8
Archive State: PAL 2 VT



The Sea Devils come to the surface and attack the Naval base. The Doctor is forced to create a machine that will awaken the creatures across the entire world.


Characters hide uncredited
Doctor WhoJon Pertwee
MasterRoger Delgado
Jo GrantKaty Manning
Captain HartEdwin Richfield
WalkerMartin Boddey
C.P.O. MyersJohn Caesar
3rd Officer Jane BlytheJune Murphy
Ldg. Telegraphist BowmanAlec Wallis
Chief Sea DevilPeter Forbes-Robertson
Sea DevilPat Gorman
Stunt ManDerek Ware (uncredited)
Stunt ManTerry Walsh (uncredited)
Stunt ManMarc Boyle (uncredited)
Stunt ManAlan Chuntz (uncredited)
Stunt ManStuart Fell (uncredited)
Stunt ManBilly Horrigan (uncredited)
Stunt ManMike Horsburgh (uncredited)
Stunt ManJack Cooper (uncredited)
Stunt ManPeter Brace (uncredited)
Stunt ManMike Stephens (uncredited)
Stunt ManMarc Boyle (uncredited)
Sea DevilBryan Nolan (uncredited)
Sea DevilSteve Ismay (uncredited)
Sea DevilGeoffrey Witherick (uncredited)
Sea DevilFrank Seton (uncredited)
Stunt ManDerek Ware (uncredited)