The existing status of the Vistula Lagoon and the Vistula Spit and the stable status of Polish-Russian agreements supplemented with regulations from the early 1990s raise doubts on the Polish side. The proposed canal that will cut across the Vistula Spit will also run through terrain that is under the special protection of both internal and European laws (Natura 2000). Currently, from a legal perspective, it is difficult to predict the successful outcome of the undertaking. The very decision to build a canal should be preceded by in-depth studies of the profitability of such an undertaking. This refers to the unique natural values of the Vistula Lagoon and the Spit. This may also present certain complications in Polish-Russian relations.