Collision in the Sea of Marmara

Two Turkish-flagged commercial vessels collided in the Sea of Marmara off the coast of Istanbul on Wednesday, 2 September 2026. The collision occurred around 3:00 a.m. local time (00:00 GMT), roughly 32 kilometres (18 nautical miles) south of the Silivri district on the western outskirts of Istanbul. The two vessels involved were the bulk carrier Tugberk Imamoglu and the chemical tanker Alsu.

While the chemical tanker emerged from the collision without visible exterior damage, authorities lost all radio and telecommunications contact with the Tugberk Imamoglu immediately after the incident. Initial assessments by maritime responders confirmed no immediate structural or navigational failure on board the Alsu.

Missing crew and search operation

Turkish emergency services initiated an immediate search and rescue mission in the waters south of Silivri. The operation mobilised numerous naval units from the Coast Guard Marmara and Bosphorus Command, vessels from the Directorate General of Coastal Safety, and a coast guard helicopter to locate the bulk carrier and its 10 crew members.

The Istanbul Governor's Office confirmed the ongoing search efforts and the inability to establish contact with the cargo vessel.

“It is currently impossible to establish contact with the cargo ship Tugberk Imamoglu and its 10 crew members.”

Attempts by the Search and Rescue Coordination Centre to contact the vessel yielded no response, and calls to the mobile phones of the crew members failed to connect. The Turkish Directorate of Maritime Affairs stated that the bulk carrier is presumed to have sunk in the Marmara waters.

“The Tugberk Imamoglu is not responding to any calls and its crew's mobile phones remain unreachable despite attempts by the Search and Rescue Coordination Centre. It is presumed that the cargo vessel has sunk.”

Tugberk Imamoglu90

Alsu91

Tugberk Imamoglu

90 m

Alsu

91 m

Data from the article text

Vessel profiles and scheduled voyages

Data from the Istanbul Chamber of Maritime Commerce identifies the Tugberk Imamoglu as a 90-metre bulk carrier operated by the Turkish shipping company Zeybe Denizcilik. The cargo ship was voyaging from the Mediterranean port of Iskenderun in southern Turkey to the Black Sea port of Karadenizeregli. Official statements did not specify what cargo the vessel was carrying during its northward journey.

The second vessel, the Alsu, is a 91-metre chemical and oil products tanker owned by Ozpulathane Deniz Tasimaciligi. Maritime tracking data recorded that the tanker had departed from the industrial port of Kocaeli, east of Istanbul, and was sailing southwest toward the Aegean port of Aliaga.

Maritime corridor through the Turkish Straits

The collision took place along the central shipping route connecting the Turkish Straits system. The maritime passage encompasses the Bosphorus Strait to the northeast and the Dardanelles Strait to the southwest, flanking the Sea of Marmara to form the only commercial shipping link between the Black Sea and the Mediterranean.

Hundreds of thousands of commercial vessels transit between the Mediterranean and Black seas through these waters each year, transporting oil, bulk commodities, and container cargo. Search and rescue operations remain active off Silivri as naval teams continue scouring the surface for the 10 missing sailors.