[1]. “Submarine Engineering of To-day.” By Charles W. Domville-Fife. (London: Seeley, Service & Co. Ltd. 1914.)
[2]. Sunk October, 1914.
[3]. The Narval, the first of this type, has been removed from the effective list.
[4]. It is very doubtful if these two boats were delivered before the outbreak of war.
[5]. The U.18 was sunk by a British patrol in November, 1914.
[6]. “Submarine Engineering of To-day.” By Charles W. Domville-Fife. (London: Seeley, Service & Co. Ltd. 1914).
[7]. As it is almost impossible for a submarine, when totally submerged, to steer a perfectly straight course, the table above each chart shows the approximate average loss and gain on each mile. It must also be remembered that the submarine in actual practice need only reach the torpedo firing line.
[8]. “Submarines of the World’s Navies.” By Charles W. Domville-Fife. (London: Francis Griffiths.)
[9]. “Submarines of the World’s Navies,” By Charles W. Domville-Fife. (London: Francis Griffiths.)