The aim of this paper is to identify and quantify the direct economic effects resulting from navigational restoration of the Dąbie Lake inland fairway, a part of the West Pomeranian region (PL) transport system that runs across the Dąbie Lake. This narrow and shallow inland fairway constitutes the bottleneck for inland waterway freight transport, which must therefore use the sea fairway and thereby incur extended time, increased cost, and reduced efficiency of inland waterway transport. The paper’s second section presents the transport and microeconomic effects that restoring the fairway’s navigability across Lake Dąbie would have on the inland navigation system, thereby increasing the capacity, effectiveness, and safety of inland waterways freight traffic. Restoration of the inland fairway would significantly reduce generalized and external costs of inland waterways transport.