Submarine Deck Logs

Deck logs maintained by submarines during the World War II and early post-war period appear to be nearly identical to logs maintained by other surface vessels. However, owing to the sensitivity of underwater warfare, and the fact that deck logs are generally either unclassified or set at a low classification level, it is uncommon for logs to contain much information about actual warfare operations. That information is generally seen in submarine war patrol reports. The National Archives is in custody of declassified war patrol reports from 1941-1945 (National Archives Identifier 305243) and additional war patrol reports dating from 1946-1953 that for the moment remain classified. Patrol reports beyond 1953 remain in the custody of the Navy.

Beginning in the 1960s, deck logs of underway submarines became vague and uninformative. This is as a result of the changes to how deck logs were to be maintained as stated in Chief of Naval Operations Instruction (OPNAV INST) 3700.1 (versions A-H).  In this instruction, it states that when a vessel is conducting “Special Operations,” then only non-operational remarks can be entered into the deck log. In practice the period of the patrol may only consist of a single page that merely states that the submarine is “On Special Operations” or “Underway as before”, with no other remarks. Submarines often maintained classified (Confidential or Secret) deck logs that remain classified and some may have been included with their patrol reports.

The practice of limited information reported in submarine deck logs is summed up nicely by a New Year's Day poem from the USS John Marshall (SSBN-611) from 1974.

I CAN'T BELIEVE THE FUN WE'RE HAVING

GOOD TIMES BY THE SCORE.

I'D TELL YOU ALL ABOUT THEM

BUT THE CAPTAIN WOULD BE SORE.

TO STAY IN HIS GOOD GRACES

AND RETAIN MY RAILROAD TRACKS,

"UNDERWAY ON SPECIAL OPS"

IS ALL YOU WILL EXTRACT.