James Mason
Mr. Grimes / Voice of Killer Shark
Bernard Cribbins
Mr. Masterman / Voice of Eel
Billie Whitelaw
Mrs. Doasyouwouldbedoneby / Old Crone / Mrs. Tripp / Woman in Black / Water Babies 'Gate Keeper'
Tommy Pender
Tom
Samantha Gates
Elly
Joan Greenwood
Lady Harriet
David Tomlinson
Sir John / Voice of Polar Bear
Jon Pertwee
Salmon
David Jason
(voice)
Una Stubbs
