Dear Ms. Garrett,
Thank you for posting your request on History Hub!
The medical and Official Military Personnel Files (OMPFs) of those who served in the U.S. Navy who were separated from the service prior to 1955 are located at NARA's National Personnel Records Center, (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002. Please use a GSA Standard Form 180 to request these records.
If he died while in the Navy, Navy and Marine Corps casualty records from 1940-1989 are in the custody of the National Archives at St. Louis (RL-SL), P.O. Box 38757, St. Louis, MO 63138-1002. Please contact them for access to these records. Their email address is firstname.lastname@example.org.
We hope this information is helpful. Best of luck with your family research!