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.
790. A cursory study of routes followed by shipping from about May 24 to June 20 indicates that about 87 ships or over 60<%> of traffic in northern approach zone crossed fifteenth meridian within 40 miles between Latitude 52<°> 20<'> and 53<°>. (stop) The possibility of enemy being aware of this concentration particularly as majority of our patrol craft engaged in escort duty would seem probable (stop) The subject is presented upon possibility that some officials concerned may not have had their attention directed to this specific point.
Source Note: Cy, DNA, RG 45, Entry 517B.