Along that might be valuable to you...

Start process of requesting your Grandpas full military file. The fact that he was in Navy gives you a great chance that his file is well preserved (a fire destroyed 80% of Army & 75% of Air Force files back in the 1970's).

Here's the link to more info: https://www.archives.gov/veterans/military-service-records

You'll actually have to have your mother be the formal submitter for the information if you'd like to receive his whole file. It's currently set up that Grandchildren are not a "next-of-kin" relation, for whatever reason.

The process is fairly easy...most difficult part will be finding his Service #/ ID. Basically his military issued SSN. You can ask your mom if she has any of his records already--it might be on a paper there. If not, try a search on Fold3.com (basically Ancestry.com for anything military records) at a family history library computer.

Once you've submitted the application, it did take several months to get our package on my Grandpa (WWII vet, Navy, radioman aboard a destroyer, fought in Okinawa). At some point in the process, they do charge you $70 before sending you the complete individual file.

What ultimately will you receive?

My G-pas file had 30+ pages, from his first paperwork he filled out to join the Navy (fingerprints, physical description, signature), documents that helped me develop a timeline of his transfers in the military (basic training, specialty radio operator training at U of Wisconsin, ship to ship transfers on the way to Battle of Okinawa). What advancements in rank he had. What medals/awards he won as a result of his service. Discharge date & place. And on & on.

It is an invaluable file of papers that are priceless to me. Unfortunately, my other grandfather was in the Army during WWII, and his file was destroyed in the fire.