Bosporus Ship Traffic in 2026, Fewer but Bigger Ships, Rising Fees and Rules Written for a City

About 110 ships a day sail through the middle of Istanbul. Turkey's transport ministry counted 40,172 transits of the Bosporus in 2025, and another 44,468 through the Dardanelles, for a combined record of 84,640 passages of the Turkish Straits. Through the Bosporus alone the ministry logged 203.7 million tons of dangerous cargo: crude oil, fuel, chemicals and gas, carried past waterfront homes, ferry piers and some of the most expensive real estate in Turkey.

The headline number hides a long trend. Bosporus traffic peaked in 2007 at 56,606 ships and fell almost every year after, to 35,146 in 2022. It has recovered a little since, but the ships are bigger, so tonnage has held up far better than the count. The Bosporus now carries fewer vessels and more cargo, which concentrates the risk in fewer, larger hulls. Chemical tankers are the one category that has grown steadily.

Photo: Alexxx1979, CC BY-SA 3.0, via Wikimedia Commons

The first half of 2026

The war has not emptied the strait. In the first six months of 2026, 19,277 ships passed the Bosporus and 20,941 the Dardanelles, about 2 percent fewer in total than a year earlier. The mix has shifted. Ukrainian grain ships now come down from Odesa and the Danube ports instead of out of a blockaded sea. Russian crude and products come from Novorossiysk and Tuapse, a growing share of them on ageing shadow-fleet tankers (more in the shadow fleet). Kazakhstan's oil, loaded at the CPC terminal near Novorossiysk, comes through as well. Since the summer of 2026 all of it has crossed a sea where drone strikes on merchant ships are a weekly event (Black Sea war and shipping).

Istanbul's cruise trade is the one part of the traffic that is growing fast. Cruise calls rose from 204 ships in 2024 to 265 in 2025, carrying about 626,000 passengers.

How a ship gets through

Under the 1936 Montreux Convention, merchant ships have the right of free passage, day and night, and Turkey can't make them stop, take a pilot or pay a toll. What Turkey can do is regulate how they navigate, and it has done so in layers. A traffic separation scheme, with one lane northbound and one southbound, has been in force since July 1994 and was approved by the International Maritime Organization a year later. A radar-based vessel traffic service, run from stations along both shores, has watched every ship since 30 December 2003. The current traffic regulations date from 2019 and are updated by directive.

Pilotage stays voluntary for ships in transit, but the authorities strongly advise it for anything 200 metres or longer, and most large ships take one. In 2025, 24,608 of the ships passing the Bosporus, 61 percent, carried a Turkish pilot. Since the first rules of 1994, large ships carrying dangerous cargo have been spaced so that only one is in the strait at a time, and big ships must wait outside when the current runs too hard or visibility drops below a mile; in thick fog the strait closes altogether. Ships that break down in the Sea of Marmara now need a survey before they are allowed back into either strait.

The reasons are physical. The Bosporus bends sharply around the promontories at Kandilli and Yeniköy, where ships must swing their heading by 45 and 80 degrees, and the surface current can run at seven or eight knots between Kandilli and Aşiyan. Fog, sudden squalls and hundreds of ferries cutting across the lanes add to it. The worst accidents, the Independenta in 1979 and the Nassia in 1994, both burned in the strait and killed dozens of sailors between them.

The lighthouse fee that is really a toll

Montreux lets Turkey charge for lighthouses, sanitary checks and rescue services, set in gold francs. For 39 years the fee was 80 US cents per net ton. In October 2022 a presidential decision raised it to 4.08 dollars, by revising the conversion rate for a currency that hasn't circulated in decades. It has gone up every July since: 4.42 dollars in 2023, 5.07 in 2024, 5.83 in 2025 and 6.70 from 1 July 2026, more than eight times the old rate. The ministry expected 254 million dollars from passing ships in the year to June 2026, against 38 million in 2021-22.

The timing was not an accident. The first fivefold jump came in the autumn of 2022, as the lira collapsed and inflation in Turkey passed 80 percent after Erdoğan forced the central bank to keep cutting interest rates. Foreign shipowners paying in dollars became a small, reliable source of hard currency for a government that had burned through its reserves. The fee applies only to ships that pass without calling at a Turkish port.

For now the shipping industry pays and grumbles, because there is no other way into the Black Sea.