Turkey will raise the fees charged to commercial ships making nonstop passages through the Bosporus and Dardanelles without calling at a Turkish port by nearly 15 percent on July 1, Transport and Infrastructure Minister Abdulkadir Uraloğlu announced Friday.
The two waterways, known as the Turkish Straits, form the only maritime passage between the Black Sea and the Mediterranean.
The Bosporus runs through İstanbul and connects the Black Sea with the Sea of Marmara, while the Dardanelles links the Sea of Marmara to the Aegean Sea.
The rate will increase from $5.83 to $6.70 per net ton, a measure based on a vessel’s net tonnage rather than the weight of the cargo it carries.
Charges for ships making nonstop passages are governed by the 1936 Montreux Convention, which guarantees freedom of passage for merchant vessels in peacetime while allowing Turkey to collect fees for specified services.
The convention permits charges for sanitary inspections, lighthouses and navigation aids and life-saving services.
The fees are listed in the convention in gold francs, a historical monetary unit, and converted into dollars according to a rate set by Turkey.
Uraloğlu said Turkey charged commercial ships 80 cents per net ton from 1983 until October 7, 2022, when a presidential decision raised the figure to $4.08 after 39 years without an adjustment.
The government then increased the rate to $4.42 in July 2023, $5.07 in July 2024 and $5.83 in July 2025.
The new $6.70 rate represents an increase of 14.9 percent from the current figure and is more than eight times the rate applied before October 2022.
Uraloğlu said Turkey expects to collect $254 million from strait passages during the 12 months ending June 30, up from $223 million in the previous 12-month period.
The government collected $38 million between July 1, 2021 and June 30, 2022, before it revised the gold franc conversion rate.
Uraloğlu did not provide a revenue forecast for the 12-month period beginning July 1, when the new tariff takes effect.
The Montreux Convention was signed in Switzerland on July 20, 1936, and remains the main international agreement regulating commercial and military passage through the Turkish Straits.