The importance of maritime shipping for the Swiss economy is not reflected in official statistics of the Swiss Federal Customs Administration – high-sea vessels are not registered as a mode of transport for the import and export of goods to and from Switzerland. Thus, the primary study objective is to highlight the importance of high-sea shipping for the trade flows of the Swiss Confederation. Therefore, quantities and values of Switzerland’s maritime trade flows will be estimated differentiated by commodity groups and vessel types including trends in the maritime sector relevant for the Swiss Confederation. More than 90% of the total volume of intercontinental trade between Switzerland and its trading partners is carried by ocean-going vessels. High-sea shipping dependency is not to be reduced to intercontinental trade flows only. Due to upstream and downstream transport stages that are a directly part of a supply chain configuration, substantial proportions of continental foreign trade depend on high-sea shipping as well.