World War II Submarine Patrol Reports

beforeafterDuring World War II, Navy regulations required submarine Commanding Officers to submit patrol reports when they returned to port. During WWII, over 1,550 patrol reports were generated. All of these reports were origianlly classified as “Secret” or “Confidential.” For many years, they have existed only on microfilm.

These reports, all 62,000 pages, have been reproduced in digital form. Although these reports are available to researchers who visit the library, they are now available on-line at the HNSA (Historic Naval Ships Association) website. There are approximately 14 Gigabytes of PDFs.

Although the prescribed format for the reports evolved during the war years, the chief function of the operational war patrol reports was always to keep the Commander-in-Chief, U.S. Fleet, and others apprised of the records of submarines in carrying out their primary mission of sinking enemy ships. The reports also provided information on other activities engaged in by submarines, such as reconnaissance, mine laying, and rescue efforts. The collective reports of the individual submarines enabled wartime decision makers to assess the overall results of missions and to make recommendations based on those assessments.

In the years following World War II, the surviving submarine war patrol reports were collected and filed by the Operational Archives Division of the Naval Historical Center, under the direction of the Chief of Naval Operations. This collection of reports was transferred to the National Archives in 1991. The collection provides a comprehensive survey of the activities of U.S. submarines during World War II and is also quite useful in researching the history of individual vessels.

Records Description

The U.S. submarine war patrol reports are arranged alphabetically by submarine name or alphanumeric designation, and in chronological order by the approximate date order covered by the report. For the most part, reports for each patrol are numbered sequentially. Variations on this practice occur for the following vessels: Gurnard, Tambor, Triton, and Trout. Some patrol reports for the following vessels are missing, as indicated by gaps in patrol numbers:Bass, Haddo, Herring, Narwhal, R-1, R-6, R-7, R-9, R-12, R-18, S-11, S-12, S-14, S-16, S-18, S-31, S-32, S-40, S-46, S-47, Shad, and Thresher. These missing patrol reports presumably no longer exist. The fact that patrol reports end abruptly does not necessarily mean that the submarine was sunk; it may have been decommissioned. Researchers can refer to the Dictionary of American Naval Fighting Ships for disposition of the submarine.

While the bulk of the collection consists of war patrol reports written during wartime, some prewar patrol reports are included. All of the reports are typed; most are mimeograph copies. Photostat or carbon copies have also been found.

The submarine war patrol reports for 1941 through late 1943 consist of daily narrative summaries of the vessels’ location and activities. The reports are usually followed by additional summary information relating to such topics as meteorology, physical and mechanical condition of the submarine, and attacks against the enemy. These early reports may relate to a number of other topics as well.

Reports submitted from late 1943 through 1945 are normally much more detailed than the earlier reports, and almost uniformly adhere to a standardized format. The elements of the later reports are as follows:

A. Prologue
B. Narrative (date and time)
C. Weather
D. Tidal Information
E. Navigational Aids
F. Ship Contacts
G. Aircraft
H. Attacks
I. Mines
J. Anti-submarine Measures and Evasive Tactics
K. Major Defects
L. Radio
M. Radar
N. Sound Gear and Sound Conditions
O. Density Layers
P. Health, Food, and Habitability
Q. Personnel
R. Miles Steamed – Fuel Used
S. Duration
T. Factors of Endurance Remaining
U. Communication, Radar, and Sonar Counter-measures
V. Remarks

Some World War II submarine war patrol reports are appended with special mission or other reports delineating operations separate from the main task of sinking enemy ships. A final feature of most of the war patrol reports is the endorsements added by the various reviewing levels in the chain of command. The endorsements mainly consist of comments, assessments, and commendations.

Occasionally, the war patrol reports include periscope photographs and track charts. Photographs and oversized charts appended to the reports have not been saved to this format; notes indicating such omissions are included on the records. Sometimes, the reports list enclosures, usually track charts, which are no longer part of the records. The location of these missing enclosures is unknown. All other extant enclosures, as well as the full patrol reports, are included in this publication.

Finding Aids
All of the war patrol reports reproduced in this publication are listed in the Table of Contents which follows these introductory remarks.

Security Classification
The war patrol reports were originally security classified, and are marked “Confidential” or “Secret.” All of the reports have been reviewed and are marked “Declassified.”

Related Records
Closely related to the submarine war patrol reports are submarine deck logs, among Records of the Bureau of Naval Personnel, RG 24. Deck logs are daily recordings of pertinent information, including the vessel’s performance, activities, location, and personnel, as well as weather conditions and other observations.

Other related records are among Records of Naval Operating Forces, RG 313. Significant documentation can be found in the general correspondence, 1941-42, of Commander Submarine Force, Pacific Fleet and Atlantic Fleet, particularly under file designation A16-3 (warfare operations). The correspondence includes pre-World War II reports and other information concerning the activities and conditions of some submarine squadrons, scouting forces, and individual vessels.

The Operational Archives Division of the Naval Historical Center holds World War II patrol reports for selected Allied submarines, mostly those of the United Kingdom.