Abstract
The thesis provides for information regarding the navigational entitlement in the Vistula Lagoon. To explain the matter, it examines other cases with similar problem. These include 1) the Curonian Lagoon, the Kerch Strait and the Sea of Azov and the Great Lakes. Also, the thesis examines the duty to cooperate of the states bordering the bodies of water with a single-access route. It describes the duty to facilitate the navigation and the passage in the Vistula Lagoon.