Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters, to Secretary of the Navy Josephus Daniels
March 8, 1918.
From: Force Commander.
To: Secretary of the Navy (Operations).
Subject: Convoying with submarines.
Reference: (a) Opnav letter of 8 February, 1918.
Enclosure: One. Letter forwarded with Reference (a).
1. The comments of the General Board are concurred in. The proposal has several times been set forward of utilizing submarines to cruise ahead of mercantile convoys, and act as antennae in the hope that the convoy would lure enemy submarines into a position from which a successful attack might be delivered by our submarines. Aside from the practical difficulties of recognition signals and so forth, the element of weather alone is sufficient to defeat this plan of operation.
2. The following comments are made on the paragraphs of Lieutenant Todd’s letter:-
In paragraph 1 it is stated that “Submarines almost invariably come to the surface to view their victim and interrogate survivors” and that “English submarines destroy about half the enemy submarines accounted for”.
Enemy submarines have become very wary. It is extremely rare that a submarine shows himself unless he is operating in an area free from the usual patrolled areas, and only after the vessel attacked has been sunk. Even then his presence on the surface may be for a few minutes only.
English submarines thus far have destroyed approximately 20 enemy submarines. There is great difficulty in finding favorable opportunities for attack and for delivering a successful attack, as the enemy submarines utilize their hydrophones and all other means for anticipating such attack.
3. Referring to paragraph 3, practically all inbound and outbound vessels are sailed in convoy. It would require a very large number of submarines to permit of the operation suggested, and if rough weather were encountered the scheme would be defeated.
4. Referring to paragraph 5, the large number of Mystery ships that have attacked submarines have made it extremely dangerous for submarines to come to the surface at any time when in the presence of any type of vessel. In a few instances, after a vessel has been sunk the submarine, if operating well off-shore, may come to the surface for a few moments; but in many other cases this procedure is not followed.
5. During the winter months practically all damage done by the submarine has been within 50 miles of land. The submarines are concentrated in areas like the Irish Sea and English Channel and the approaches thereto. In these areas they have been hunted both by submarines and surface craft; but enemy submarines have been very wary and have remained submerged for the greater part of the time in these narrow waters, except at night. The success of the hunting, even where the submarine was fairly accurately fixed, has not been as successful as we should like. At the present moment the field for hunting with listening devices seems to offer more promise than any other suggestion that has been put forward.
WM. S. SIMS