This is from: http://www.usmm.org/contact.html Ship Movement Report Cards, WWII
These records consist of file cards for Merchant Marine ships having Navy Armed Guard on board, and some Army Troop Transports. Movement report cards detail the travel information of ships throughout WWII. They list ports of arrival, due dates, dates of arrival and departure, and convoy designations. Information you must provide: name of ship, dates of interest. Helpful Information: Convoy designation. Records of Individual Convoys, WWII
Operations of convoys and independent ships including detailed records of each convoy and activities of individual merchant ships. Information you must provide: Convoy designation or name of ship(s) participating in convoy; and dates of convoy. Helpful information: places of departure and/or arrival of convoy and dates. Armed Guard Reports
Reports usually include U.S. Navy Armed Guard crew lists, voyage reports, data relating to armaments and supplies provided by U.S. Navy, correspondence relating to recommendations for medals for members of the Armed Guard crew, orders, etc. Information you must provide: name of ship, dates of interest (spring 1942 to winter 1945). Helpful information. ship's former name, if any. Write to:
Modern Military Records Unit
National Archives at College Park
8601 Adelphi Road
College Park, MD 20740-6001
They will respond with an estimate of the cost of the research. Include in your letter the full name, address, and telephone number of the individual making the request. Please note: When making a request, do not send payment until you receive a price estimate/order form.
National Archives ask that you limit your requests to 5 items per letter. Upon receipt of your request, they will survey the records and send you a price estimate/invoice for obtaining copies. Once you return the invoice with your payment, they will then send you the reproductions. You should allow at least 10-12 weeks for this process - from the date you send your initial request to the final receipt of reproductions.
The Modern Military Records (NWCTM) is new to me, but it appears they may hold the convoy records. Here is another Naval Records website with addition links that may aid in the search: http://www.mrfa.org/Navy.Records.htm