Stingray - Season 1 Episode 33 Sea of Oil

Atlanta is captured by an undersea race when Stingray investigates the collapse of an oil drilling rig. She discovers that the creatures only attacked the rig out of self-defence, believing that their home was under attack. Unfortunately, a bomb has been planted aboard Stingray that will explode when the ship dives. Atlanta makes a desperate effort to contact Stingray but, fortunately, Marina's pet seal, Oink, discovers the bomb and pushes it off in time