Here's a tantalising prospect for any would-be treasure seekers out there – the mysterious story of the "El Dorado of the Seas".
That is the name given to the treasure-laden wreck of the Merchant Royal, which sank somewhere in the sea off Land's End, Cornwall, on September 23rd, 1641. In the 375 years since then, treasure hunters have searched for the wreck and its contents, rumoured to be worth hundreds of millions of pounds in today's money.
Built in London's Deptford Dockyard in 1627, the Merchant Royal spent its last three years afloat as a merchant ship trading with Spanish colonies in the West Indies. With England and Spain for once at peace with each other, it was a prosperous trade for the wealthy merchants who operated the ship and her sister-ship, the Dover Merchant.
In the late summer of 1641 both ships were making their way back to England from the West Indies, laden with valuables, when they were forced to call into the Spanish port of Cadiz. The Merchant Royal had begun leaking badly and needed urgent repairs before continuing her voyage to London.
While in port, a Spanish ship, also moored there, caught fire just before she was due to carry treasure to convert into wages for Spain's 30,000 soldiers in Flanders. Seeing a chance to make some extra money for his vessel's owners, the Merchant Royal's Captain John Limbrey volunteered to take on the treasure and deliver it to Antwerp on his way home, for a healthy fee.
His offer was accepted and when the Merchant Royal set out from Cadiz she was carrying at least 500 heavy bars of gold, 400 bars of Mexican silver, almost half-a-million pieces-of-eight and other coins, and as much again in fine jewellery and precious stones.
Unfortunately her repairs had been hastily carried out and she was now carrying significantly more weight. She began taking on water again soon after leaving port and when heavy weather set in between Land's End and the Scilly Isles, the doomed ship began to sink. Eighteen of her crew were drowned, but Captain Limbrey and 40 of his crew got away in boats and were rescued by the Dover Merchant, following behind.
The ship, though, had gone to the seabed, together with her immense treasure and the fortunes of many merchants. Not surprisingly, there have been many attempts to locate the wreck and salvage the treasure, but so far they have all been unsuccessful.
The USA-based Odyssey Marine Exploration company has spent years and invested millions in searching for the wreck. In 2007 it recovered silver and gold coins worth an estimated £360 million from a shipwreck, leading to intense speculation that it had finally located the Merchant Royal. In the event it turned out to be a Spanish galleon, possibly the Nuestra Señora de las Mercedes, which sank in 1804, more than 60 years after the Merchant Royal.
The search goes on, but for now all that anyone knows is that somewhere on the seabed near the mouth of the English Channel lies one of the richest shipwrecks of all time, just waiting to be discovered.