Looking at the above list, one can see that the majority of the losses were due to mines. Losses by direct contact with the enemy were infrequent. This, of course, is because only a Fleet holding command of the sea can institute regular anti-submarine methods and patrols. Our boats were working in and around the Bight, and were taking the risks of mine-fields all the time. The five wrecks show that navigational difficulties are increased in war-time. This was found also by surface vessels. The Dardanelles took their toll; it was easy to do damage to traffic in the Marmora from a well-trained submarine, but getting in and out of the Narrows was no simple matter. Of the two sunk by air bombs, one was alongside in harbour, and the other was destroyed by an Allied aircraft which mistook her for a U-boat; the submarine could have easily dived and avoided attack, but was under the impression her unfortunate opponent was only closing in order to make signals. The three others sunk in error by our own side show that a submarine's risks are great even on her own coast, and that methods of identification can never be perfected. The enemy suffered more than we did from errors. They had several clashes between their own destroyers: on June 1 (the morning after Jutland) the _Stettin_ was fired on by the whole of their 2nd Battle Squadron; while one U-boat in 1914 successfully stalked and torpedoed another (U 5), thinking it was one of our own. VI I have mentioned the fact that Submarine "A E 2" (Lieut.-Commander Stoker) was the first boat to get into the Sea of Marmora. Her experience is worth relating, especially in view of the fact that she was an Australian Navy boat, and that her trip was made simultaneously with the Gallipoli landing. She entered the Straits at 2.30 A.M. on 25th April 1915, and continued upon the surface till, being fired on from the northern shore, she dived at 4.30 A.M., and proceeded at 70 feet depth through the mine-field. Her despatches say:-- "During the ensuing half-hour or so the scraping of wires against the vessel's sides was almost continuous, and on two occasions something caught up forward and continued to knock for some considerable time before breaking loose and scraping away aft."