In March the British failed in their attempts to send a fleet through the Dardanelles Straits, thanks to minefields and Turkish shore batteries. They have had more luck with a submarine attempt to attack through the Straits. Lieutenant-Commander Martin Nasmith successfully brought the E11 submarine through the Dardanelles on the 17th of May, sailing under the mines and out of sight of the Turks.
Now the E11 is in the Sea of Marmara, the wider body of water that lies between the Dardanelles and Constantinople, the Bosporus and the entrance to the Black Sea. Nasmith’s mission is to disrupt Turkish attempts to reinforce their forces in Gallipoli by sea.
Until now the Turks have not had to worry about their shipping in the Sea of Marmara being attacked, but Naismith changes that. Today he sinks a Turkish gunboat and several other vessels. This all seems a bit too easy: the Turks have nothing to defend themselves against this British submarine.
Martin Naismith (Wikipedia)