Day 2: In the Sea of Marmara

In the early hours of December 28, the Bulgarian military research/survey vessel Sv. Sv. Kiril i Metodii passed from the Black Sea to the Sea of Marmara through the Bosphorus. At 8:30 a.m. local time, the vessel entered the approaches to the strait after receiving permission from the Turkish authorities. The ship was escorted by a coastguard cutter as it crossed the 30 kilometres separating the European and Asian parts of Turkiye and Istanbul. 

At around 10:30 local time, the ship left the Bosphorus, heading for a berth for bunkering in Zone B, where local authorities indicated a point with coordinates for the ship to anchor. Currently, a barge is waiting to refuel the ship by hooking up a hose to its system, navigator Hristo Hristov explained. 

"We crossed the Bosphorus in 2 hours with no significant problems and we have just crossed the Golden Horn. Right now we are approaching a bunkering berth. The fuel will last us until we reach Argentina at Mar del Plata where we will replenish the stocks because from now on we will not allow the fuel to go below the mandatory level. We hope the refuelling to last no more than four hours," Commander Nikolai Danailov said.

The Bosphorus Strait is one of the most difficult to navigate in the world due to the heavy traffic of passing merchant ships, ferries and other small vessels, as well as its current, which reaches up to 6 knots, and the sudden changes in weather during the autumn-winter period. At its widest part it is about 3,700 metres and at its narrowest about 750 metres (between the Anadoluhisari and Rumelihisari fortresses). The depth of the Bosphorus varies between 36 and 124 metres.

Sv. Sv. Kiril I Metodii is on a historic first voyage to Livingston Island to support the 31st Bulgarian Antarcic expedition. It is expected to last some 40 days one way.