Same situation when i navigate through Dardanelles towards Black Sea.
I believe there is an issue with the accuracy of the maps.
For instance being in mode "(Geo)Physical" Map, if i double click on the Dardanelles, where is blue(i.e. is the sea) i am getting "Mixed" word. This is a place where i can get my ship Moored and anchored despite the fact that the ship is in the middle of the sea.
Also, if i double click on the land area i also get the word "Mixed" written on the screen and i could navigate the ship through this area, despite the fact that actually there is no water there.
So, i believe that the ship's engine dies because the map is "Mixed", no water.
Also, if there is an island-a rocky one and the double click says "Water", then the ship could navigate through the island without any issues.