Office of the Chief of Naval Operations to Captain Frederick L. Oliver, Commander, Submarine Base, New London, Connecticut; and to Naval District Commandants
T E L E G R A M .
20 June, 1918.
To : Commander, Submarine Base.
Commandants first to eighth Naval Districts inclusive.
Commandants fifteenth Naval District.
Following report received. Quote British Steamship British Sovereign on June 18th sighted a Submarine flying an American flag. Steamer had gun trained on her awaiting for a movement but nothing developed and continued on her course. There was no warning of an American Submarine in this vicinity and only identification submarine had was an American flag unquote. Many similar reports being received. United States of America Submarines on patrol should be instructed to use every effort to avoid being sighted by shipping and consequently possible damage through attack by gun fire. 20020.
Source Note: Cy, DNA, RG 45, Entry 517B.