Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters, to Secretary of the Navy Josephus Daniels
SENT: June 20, 1917. TO: Admiralty.
THROUGH: Admiral Sims
With full appreciation of the importance of Naval activities in other areas the conclusion cannot be escaped that the approaches to the Irish Sea and Channel are the critical areas in which the safety of our lines of communication are at stake and hence where the issue must be decided. Owing to the necessity of convoying troops the forces available in this area will in the next two days be reduced to six destroyers and six sloops in active operation and four of each in reserve.
Even if worked to the limit this is insufficient either to patrol the area or convoy valuable cargoes, much less both and if more forces are not made available this must necessarily result in the loss of an excessive amount of shipping particularly if the enemy should concentrate his efforts in this area.
The situation existing in this area yesterday 18th June and to-day, Tuesday, which is now more or less typical was very serious. the majority of the forces were escorting single ships with valuable cargoes inward-bound thus leaving all shipping following them unprotected.
With attacks on ships with single escort becoming more frequent, it would seem suicidal not to put the convoy system into the fullest possible effect immediately and applied to all merchant vessels thus forcing submarines at least to encounter anti-submarine craft in order to attack shipping.
I feel reasonably certain that the United States will soon increase their destroyer forces in this area and that additional anti-submarine vessels will be sent as soon as a practicable.
Source Note: Cy, DNA, RG 45, Entry 517B.