In order to adapt to structural changes in world trade, container ship owners have developed their transport services. Thus, the unit transport capacity of container ships has been multiplied by 3 in the space of 20 years. The maritime transport of containers has developed very speedily and there have been changes in the strategies of shipping companies. These giants of the seas, put into service on the maritime trades linking the world's main production and consumption markets, have led to the repositioning of ships on secondary maritime spaces. This is known as cascading. The objective of this paper is to study the impacts on the ports and the maritime network of the Baltic Sea. For this purpose, we will carry out an analysis of the evolution of container ship calls from 2012 to 2020 (number of calls, capacity offered in calls, ...) followed by a graph analysis to study the evolution of the maritime network.