This ancient clip from The Unpleasant World of Penn and Teller isn't all that remarkable for the trick, in which a submerged Teller attempts to beat Houdini's breath-holding record while Penn flubs a card trick again and again. Penn and Teller have been doing that trick since the early 80's: they actually did it on Saturday Night Live at one point, when the device that allowed Teller to breathe malfunctioned, and they just managed to complete the trick in time before Teller had to signal someone off stage with an axe to get him out of the tank. What makes it remarkable is the presence of an utterly dry John Cleese as Penn's assistant.
It's hard to tell if Cleese is bored by the trick or is simply a classy enough performer not to upstage Penn and Teller on their own show with witty rejoinders. I'm going to bet on the latter.
