This collection consists primarily of letters exchanged between Edison and Secretary of the Navy Josephus Daniels, along with related correspondence. Many of the typewritten letters are accompanied by drafts in Edison's hand. The documents in this folder are from March-August 1917. They pertain to Edison's plan to use submerged buoys (similar to the whistling buoys used by the Lighthouse Board) to detect enemy submarines along the eastern seacoast from Nova Scotia to Florida. Another copy of Edison's letter of May 28, 1917, with a notation that the original letter was sent to Chief of Naval Operations William Shepherd Benson, can be found in the Josephus Daniels Papers—Thomas A. Edison Correspondence, Library of Congress. This project is described on pp. 172-174 of Lloyd N. Scott's Naval Consulting Board of the United States. A transcription of Edison's letter of April 16, 1917 appears on those pages. Additional material regarding submarine detection can be found in Reports 9, 27, and 31.

Included in the correspondence are several references to Edison's unsuccessful attempts to charter a private yacht to conduct his submarine detection experiments and to Daniels's efforts to secure a naval vessel for Edison's use. To facilitate Edison's research, a 217-ton steam yacht was acquired by the Navy in July 1917 and commissioned as the USS Sachem on August 19. The Sachem was Edison's base of operations from the time of its commissioning until early October, when he departed for Washington, D.C. It continued to be used for Edison's research until it was returned to private ownership in January 1919.