Get Smart (1965)

S2E9 Rub-a-Dub-Dub . . .Three Spies in a Sub

Max and Agent 99 find themselves imprisoned aboard a KAOS submarine under the command of the devious Siegfried. As they navigate their precarious situation, they must devise a clever escape plan before time runs out, all while dealing with the quirky challenges that come with being trapped beneath the ocean.