Richard Hammond - TV presenter and self-confessed mystery addict - is on a quest to uncover the truth behind the rumours and whispers around events in the world's waters.
Was the lost city of Atlantis real? Do mermaids exist outside stories? And where is everybody who was on the Marie Celeste?
Don't miss this instalment in the incredible series by Britain's best-loved TV personality. Explore the world's greatest mysteries - all from the comfort of your armchair!