20 Things You Probably Don’t Know About Turkish Straits

Turkish Straits - Bosphorus

20 Things You Probably Don’t Know About Turkish Straits

The Turkish Straits have been and continue to be one of the most important waterways in the world. For centuries it has served as the economic lifeline for the Black Sea region and has been the soul of Istanbul, a UNESCO cultural heritage city.

1. Since 1936 international shipping throughout the world has grown, and likewise the Turkish Straits witnessed annual traffic increase from 4500 vessels a year to nearly 55,000 vessels a year.

2. The Strait of Istanbul, the Sea of Marmara and the Strait of Çanakkale are considered to be, under relevant international conventions, a single navigational route that connects two open seas, namely the Aegean and the Black Seas. To sail between these two seas requires navigating 164-nautical miles through the Straits of Istanbul and Çanakkale, both of which individually qualify as national straits, and the Marmara Sea, which is an internal sea of Turkey

3. The Turkish Straits consist of the Istanbul Strait (17 nm in length), the vessel-navigating area of the Marmara Sea (110 nm in length) and the Çanakkale Strait (37 nm in length). The total length of the Turkish Straits is 164 nm and it is open to international maritime vessel traffic under the control and regulation of the Turkish Government

4. Apollonius of Rhodes, in the third century BC, described a “Pilot” in his book The Argonautica as a “skillful helmsman.” Furthermore, the pilotage to which he referred took place in the Strait of Istanbul (The Bosporus). The Legendary hero Jason led his Argonauts through the Bosporus to reach Colchis, in search of the “Golden Fleece”. This journey has been dated back to 1200-1300 BC. Passing through the Bosporus was one of the biggest challenges on the route to Colchis.

5. While in 1938, a total of some 4.500 ships passed through the Strait of Istanbul transporting a total cargo of approximately 7.500.000 tons, by 2005, the number of ships navigating through the Straits increased to 54.794; and of these, 10.027 carried hazardous cargo; the total figure of such cargo amounting to 143.567.196 metric tons.

6. Today, an average of twenty-seven ships carrying hazardous cargo pass through the Strait of Istanbul each day. Likewise, of the 49.077 ships that passed through the Strait of Çanakkale in 2005, approximately 18 percent of the cargo carried was hazardous. On average, twenty-four ships pass each day through the Strait of Çanakkale.1 Although the physical structure, the geomorphologic and hydrological nature, and the meteorological conditions of the Turkish Straits have remained unchanged, the total number of ships passing through the Straits has increased twelve times during the past seventy years.

7. Boats and car ferries cross it approximately 2500 times every day carrying an estimated two million people between two continents.

8. The tragic and devastating 1979 Independenta/Shipbroker tanker accident raised public awareness of the risks brought by shipping and dangerous cargo to the Turkish Straits. It sparked a debate which lasted for many years on the need to improve the safety of the Turkish Straits.

9. The most catastrophic of these accidents occurred in 1979 when the M/V Evriali collided with M/T Independenta, the latter fully laden with oil. The collision resulted in the tenth most serious oil spill in the world as a total of 95.000 tons of crude oil spilled and burned into the Strait. Forty-three crew members lost their lives.

10. For centuries, the Turkish Straits been known as a difficult waterway to navigate for vessels, as well serving as a strategically and commercially important waterway for maritime transport. In addition to its geopolitical and strategic importance, as the only waterway between the Black Sea and Mediterranean Sea, the Turkish Straits are also a highly congested route for international maritime traffic.

11. The narrowest bend of the Istanbul Strait is located between Aşiyan and Kandilli where the Strait measure a mere 698 meters, The Aşiyan and Kandilli bend requires a course alteration of 45 degrees and is only one of twelve sharp bends in the Istanbul Strait. The Yeniköy bend is another difficult area in the Istanbul Strait where the course alteration is 80 degrees. Another danger for the navigation is the current speed, which can reach up to 7-8 knots.

12. The Straits are further characterized with four different types of currents. The Black Sea is nearly 30cm higher than the Aegean Sea which creates a surface current direction that generally moves from north to south and can reach up to 7-8 knots. But due to the low sea water density of the Black Sea a second deep current flows from south to north.

13. In addition, there are local counter currents and the orkoz current which is caused by strong southerly winds, all of which make navigation in Turkish Straits difficult

14. Over the years the Turkish Straits have been the victim of many accidents that have endangered both the lives of crew, the population of as well as caused serious damage to the marine environment. In 1963 a woman was actually killed in her bed after a vessel rammed into her bedroom.

15. Pilotage is compulsory at Turkish ports for all Turkish flag vessels over 1000 GT and for all foreign flag vessels over 500 GT.

16. There is another legend about the Straits dating back to ancient times having to do with the name “Bosporus” itself. “Bosporus” means “cow’s passage” and according to the legend, the beautiful Io passed through this passageway when running to avoid a fly when her lover, the “boss” of Olympus, “Zeus” converted her into a cow in order to prove to his jealous wife, Hera, that she was not his lover.

17. For centuries, the Strait of Istanbul has served as a strategically vital waterway to and from the Black Sea. In 513 B.C., the Persian emperor Darius built a bridge of ships across the strait to lead his army into Greece.

18. The Treaty of London (1840) and the Straits Convention (1841) followed. These were the first international instruments to regulate passage through the Straits. Then Ottomans lost total control over the Straits under the 1918 Mondros Armistice.

19. Within the Turkish Straits system, particularly the Strait of Istanbul, which forms a winding and quite narrow geographical structure 18 nautical miles (31 Km.) in length and 700 meters at the narrowest points in width, there are numerous bends including one that require 12 course alterations for passing vessels. Some of these alterations are very sharp, in some instances more than 80 degrees.

20. The Strait of Istanbul serves as a biological corridor for thirty-three different marine species and as a passage for dolphins that were included in the list of protected wild life.