Tracy My father also was in the Merchant Marine (US Maritime Service) during WWII. I have a copy of his "Certificate of Service" which shows the "Book Number" in the upper right hand corner and that number starts with "Z" followed by a 6 digit number. The Certificate of Service lists the seaman's name, the department of qualification and his rating. It also lists the date of qualification and the port at which it occurred. Other documents that I have which include this number are: Seaman's Certificate of Identification National Maritime Union Wartime Shipping Card Certificate of Discharge It does appear that this is similar to a service number. These records were passed down to me. One suggestion on finding your grandfather's records: The Merchant Marine were never considered to be "veterans" as such until about 10 years ago when the law was changed to allow WWII Merchant Mariners to receive veterans benefits medical treatment at the VA. I believe though that they needed to make application for those benefits, they were not automatically granted. Good luck. Let me know if I can help. Dan From: <GaelEire@aol.com> > My grandfather was a tug boat captain. I understand that during WW II, > anyone who worked on the water was required to obtain a Coast Guard/Merchant > Marine pass. Following up on this tip, and after contacting several archives > (including the Coast Guard historian), I was directed to the National > Maritime Center, who holds personnel records. They informed me they can't > perform a search for my grandfather unless I provide a 'z number' or 'book > number'. > > What is a 'z' or 'book number'? Is this equivalent to a service number? How > do I find out what my grandfather's number was? The only information I > currently have is his employer during WWII and of course, all personal > information (age, address, dob, ss#, etc). > > I would be grateful for any advice or assistance on this matter. I feel as > though I'm chasing my tail! > > Take care, > Tracy