The film 'Worlds lost in the deep' is a story about the researchers of underwater archaeologists working on the excavation of an 18th-century sunken ship in the bay of Kiten. The excavations are conducted by the Center for Underwater Archaeology in the town of Sozopol, under the Ministry of Culture, and the INA Institute of Nautical Archaeology in the USA. Bulgaria is not only part of the ancient world, but the Black Sea is one of the few places where remnants of wooden ships are preserved underwater, due to the unique underwater environment. Because of the rise in the Black Sea’s water level thousands of years ago, there are preserved underwater settlements and shipwrecks. For several years, Ladislav Tsvetkov has been following the work of underwater archaeologists and is the author of numerous reports and documentaries. He is also the author of documentaries related to the ecology of the Black Sea. He works as a multimedia reporter, with his main focus being on various human activities in nature, as well as its preservation. He is also the author of the series 'Discover Bulgaria,' a collaboration between BTV and the Ministry of Tourism. Another of his series is 'Mission 360,' aired on the program 'This Saturday, This Sunday' on BTV. What’s unique about his work is that he works alone, being the author of both the filmed footage and the directing and scriptwriting.