Vice Admiral William S. Sims, Commander, United States Naval Forces Operating In European Waters, to Secretary of the Navy Josephus Daniels
SENT: July 11, 1917. TO: Secretary of the Navy
THROUGH: British Admiralty
Number ninetythree. Your dispatch 22006 concerning patrolling a single lane through danger zone received through MELVILLE July ten (stop) The plan has been fully considered in the past by the British Admiralty but not adopted for primary reason that the number of patrol craft available have been and will continue to be inadequate (stop) Another vital objection is that no matter how or how often the lane can be shifted the western end would always be clearly defined (stop) Submarines have operated to a maximum distance from Ireland of four hundred miles and sinkings are frequent up to two hundred miles (stop) Even if submarines did not attempt to attack through the patrol lines themselves, it could always attack to the westward and the patrol line would afford excellent information as to the proper areas for attack (stop) As experience shows that a vessel even when zig-zagging and accompanied by a single zig-zagging destroyer close ahead is not always immune to attack, it is apparent that unless such a proposed patrol line was very dense the submarine could undoubtedly attack successfully at any point along it (stop) As more than just one lane would have to be established and as at least one third of all patrol craft would always be resting, refueling or repairing, it seems manifest that the number of ships required for such a plan would never be available (stop)
Source Note: Cy, DNA, RG 45, Entry 517B. At the bottom of the document is a list of where copies should be filed.