Treasure hunters and scientists have for many years been looking for a shipwreck dating back to the time of the discovery of the Americas. Now they think it's been found just off the Panamanian coast. A wreck located at a depth of only a few metres, prompted American expert of Iberian shipbuilding, Professor Filipe Castro to say "this is the oldest wreck ever discovered off the coast of the Americas". Finds of cannons, wreckage and fragments support the theory that the wreck is of Spanish origin, which dates back to around the end of the 14th and beginning of the 15th century. This film traces the route of Columbus' fourth voyage to the Caribbean, which ended in disaster for him and his fleet. The contemporary diving expedition to the shipwreck, the scientific investigation of the ship and the story of the fourth voyage are all woven together throughout the fabric of this programme.