Teletubbies - Season 1 - Eps 102: How Things Swim
The Teletubbies run over to each other but the Magic Windmill spins and the Teletubbies then watch Andy Brown visiting an aquarium to learn how things swim in water, then they play an in-and-out game when a cloud appears in Teletubbyland.
About Teletubbies

Title: Teletubbies
First Air Date: 1997-03-31
Last Air Date: 2001-02-12
Status: Ended
Rating: 4.5/10 (from 152 votes)
Language: EN
Seasons: 6
Total Episodes: 365
Network: BBC Two
Genres: Family, Kids
Production Companies: Ragdoll Productions, BBC
Synopsis
Pre-school fun, fantasy and education with colourful rotund characters Tinky Winky, Dipsy, Laa-Laa and Po in a magical land called Teletubbyland.
Cast

Pui Fan Lee
Po (voice)

John Simmit
Dipsy (voice)

Nikky Smedley
Laa-Laa (voice)

Simon Shelton
Tinky-Winky (voice)

Jessica Smith
Sun Baby (voice)