Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters, to Secretary of the Navy Josephus Daniels
SENT: June 14, 1917 To; Secretary
THROUGH: Admiralty. Via Naval Attache, Washington
91. Following for United States Chief of Naval Operations from Vice Admiral Sims begins Total losses week ending 12th June 193975 tons. Pressure during latter part of week greatly increased and estimated number of submarines now operating corresponds to greatest number during worst fortnight in April. 24 submarines are known to be operating around United Kingdom the majority of which left their bases in comparatively short time which is new practice. Irregularity of enemy operations prevents accurate estimations of his plans. We must expect periods of varying activity. Principal area of activity still remains on Atlantic approach routes to South Westward of Ireland and England. Five or six apparently working in White Sea and one or more to West of Gibraltar and a large number in addition operating in Mediterranean. 43 encounters with submarines during week 7 by destroyers 13 auxiliary patrol 6 special service vessels 2 patrol cruisers 2 submarines 2 seaplanes and 11 merchant vessels 2 French and 1 Russian. Minelaying about average concentrated South-east and West Coast British Islands. 10 ships lost in one day. Defeat of submarine campaign can only be effected by increasing number of anti-submarine craft immediately.. If safety of oil and other valuable and urgently needed supplies for Allied Forces is to be insured greatly increased numbers of anti-submarine craft are necessary message ends.
Source Note: Cy, DNA, RG 45, Entry 517B. Copied to: “1st. S.L.”, VAdm. Sir John R. Jellicoe. Document is labeled with: “Copies:/Confirmation./Chronological File./Subject File.”