The Sinis protected marine area and the Island of Mal di Ventre is the subject of this documentary that takes place in the Eastern part of the Island of Sardinia. In the company of Angelo, a Sardinian diving instructor we go to discover the underwater flora and fauna of the waters around the Island of Mal di Ventre, a place of splendid tropical colors. We then dive to visit the shipwreck of the "Vaporetto": a ferryboat that went down in the Second World War, which is quite well conserved and is home to various types of fish like the groupers and also to sea slugs. We then go to visit the Cabras pool and watch the traditional fishing methods of the flat-headed mullet, a species from which can be extracted the famous "Sardinian Gold": Bottarga (Dried fish eggs) After we have seen how they harvest and transform the fish eggs and also tasted some local dishes using it, we return to the sea with our masks and flippers to enjoy the sea beds around the famous Seu Arches.