Many thanks to my dear friend, Josip Mikolcic, Croatia for sending me this beautiful souvenir sheet on envelope.
The ship on stamp is a motor cargo ship "Elhawi Star", sunken in 1982 in front of the Rijeka harbor. The ship depicted in the souvenir sheet is illustration of the cargo steamer "Vis", sunken in 1946 alongside east coast of Istria, close the entrance to Plomin Bay.
There is no official register of wrecked ships in the Adriatic, but it is believed that Adriatic Sea is the richest sea in the world concerning shipwrecks. According to some data, there maybe about 15,000 wrecks in the Adriatic.
Text source: Brochure issued by Hrvatska Posta.