Over the last few decades, thanks to modern technology, the gates of a new world under the oceans have been flung open: a world that has preserved several chapters of human history in the forms of harbours, cities, temples, statues and shipwrecks.
But this is also a treasure trove that needs protecting. International seas are largely unregulated, meaning most underwater archaeological wealth can be retrieved and sold without any obstacle.
Win Scutt finds out how the maritime treasure hunting industry has boomed in recent years.
Advances in immersion technology have now brought 98% of the world's ocean floor within the reach of archaeologists and salvage companies.But with few international protocols on underwater cultural heritage in place, many archaeologists are complaining the sea has become a free for all.
On the other hand, working all wrecks to proper archaeological standards could be very expensive and time consuming as Win discovers when visiting the site of the Mary Rose wreck in Britain.
An alternative solution is to simply leave things where they are, and when possible create a museum, or a diving trail around the site. To find out more, Win dives the world's first underwater museum in Caesarea off the coast of Israel.
First broadcast Friday 29 August 2008