Nations Rethink Free Passage as Marine Tolls Resurface in Key Waterways
A growing number of countries are considering tolls for ships passing through key waterways. These routes, often controlled by narrow straits or estuaries, have long been governed by treaties ensuring free passage. Yet recent proposals and existing practices suggest that some nations may be rethinking these agreements.
The idea of charging vessels is not new—historically, tolls were common in Europe’s busiest maritime choke points. Now, with economic pressures rising, the debate over marine tolls is resurfacing in critical shipping lanes worldwide. The concept of charging ships for passage dates back centuries. The word tariff itself comes from medieval tolls levied on vessels entering the Mediterranean through the Strait of Gibraltar. Over time, treaties like the 1868 Mannheim Convention ended such fees on the Rhine, while the 1948 Belgrade Treaty blocked Romania and Ukraine from tolling ships at the Danube’s mouth.
Today, some nations still profit from controlling vital routes. Iran reportedly earns $2 million per oil tanker passing through the Strait of Hormuz. Meanwhile, Indonesia’s Finance Minister Purbaya Sadewa recently proposed charging ships using the Malacca Strait, a key route for global trade.
Europe’s waterways remain largely toll-free due to long-standing agreements. Denmark, for example, is bound by the 1857 Redemption of Sound Dues treaty to allow free transit through the Skagerrak, with no way to exit unless other signatories agree. Similarly, the Montreux Convention keeps the Bosporus open, ensuring Ukraine’s grain exports and Russia’s Black Sea trade can flow freely. But Turkey, which controls both sides of the strait, could theoretically impose tolls by withdrawing from the treaty.
Beyond Europe, the UN Convention on the Law of the Sea (UNCLOS) bans marine tolling. Yet a third of the world’s countries—including the US and Iran—have not signed it. This patchwork of treaties and exemptions leaves critical routes vulnerable to sudden policy shifts. While treaties have kept many shipping lanes open, recent proposals and existing tolls show that these agreements are not always secure. Countries controlling strategic straits may reconsider their obligations if economic or political pressures grow. The outcome could reshape global trade routes, affecting everything from grain exports to oil shipments.
