Narration

Transcript

Note: Transcripts are generated using speech recognition software and may contain errors.
Joseph finds okay. The enormous blue whale. It's bigger than even the largest dinosaurs. It's tongue weighs as much as an elephant. Its heart is the size of a car. It has blood vessels. So why that you could swim. Now, if you think that sounds incredible, then wait until you see it discover more about the deep oceans than ever before. Until now, we've only touched the surface Blue Planet Tonight at nine o'clock on BBC one.