Surfing dolphins clip from the 2003 BBC "Wildlife on One" episode Dolphins: Deep Thinkers, narrated by David Attenborough. The educational clip narrates that the maintenance of social bonds in complex animal societies such as dolphins and humans may be the explanation for why both dolphins and humans exhibit "play" behaviors into adulthood and full maturity. Footage is from Jeffreys Bay, South Africa. AFAIK this special was never broadcast in the United States.
Check out the BBC's website often for the full video, as press reports have indicated they will put all their full programs online.