One of 12 unique ships built for the Soviet fleet, and used for secret spying in the North Atlantic ocean during the Cold War, is now available for charter after being painstakingly transformed by its owner.

La Sultana, a 65 metres long vessel, was originally named Aji Petri and built in 1962 at the Georgi Dimitrov shipyard in Varna in Bulgaria.

It was built as a Black Sea passenger ferry designed to carry cargo and people between the ports of Odessa, Sevastopol, Istanbul and Yalta.

But, in 1970, global political tension made Aji Petri invaluable to the Soviet navy as an environmental research ship and it was sent to the North Atlantic Ocean on behalf of the International Organisation of Telecommunications for unofficial spying on the US and the UK.

After the fall of the USSR, Aji Petri was assigned to a Bulgarian shipping company and resumed service as a passenger ferry between Istanbul and Yalta. Then, in 2007, the La Sultana Group transformed the vessel into a luxury superyacht fit for charter in international waters.