There are more than three million vessels on the world's sea beds, and plenty of explorers looking for them. But if they find something valuable, do they get to keep it? We talk to an arbitration lawyer about the laws governing the sea, and hear from maritime archaeologists about the perils of rummaging around on the ocean floor, disturbing long-sunken wrecks that offer a priceless glimpse into history. Some say we should leave these ships be, especially when they’re graveyards. Others say we should bring them to the surface, put them in museums to educate people, make money from them and perhaps even sell off some of their treasure.Produced and presented by Gideon Long(Image: A diver looks at a shipwreck. Credit: Getty Images)