Bruce, I am a hobbyist who enjoys studying WWII, and sharing history/research info with other novices. Until you receive a response from an expert researcher, or until you secure the services of a professional, here is some info you might be able to use. Some are resources I have used researching my own family, others are those I have only read about, or found online. Please be sure to verify all to your own satisfaction.
Even though you are not related, you should be able to get some info from his personnel record through the NPRC in St. Louis. (They had a disastrous fire in 1973. However, they indicate that Navy Dept personnel records were not affected.) Info on that resource can be found at this web page: http://www.archives.gov/st-louis/military-personnel/index.htmlhttp://www.archives.gov/st-louis/military-personnel/index.html (There is info at that site that indicates the type of info available to non-relatives.)
You can also send for his Individual Deceased Personnel File (IDPF). As I understand it, you do not have to be related to get this info. Send your request to: US Total Army Personnel Command ATTN: TAPC-PAO (FOIA) 200 Stovall Street Alexandria, VA 22332-0404 Be sure to cite the Freedom of Information Act in your request. (The above references "Army" but personnel at this command told me via telephone that they also hold Navy/Marine IDPF's for WWII.)
Another resource I have read about, but have not used: Information on personnel who may have died while in the U.S. Navy is recorded on index cards. A description of how the individual was killed is usually included. These may be requested from: Officer in Charge Naval Medical and Dental Affairs Mortuary Affairs Branch PO Box 886999 Great Lakes, IL 60088-6999 Phone 800-876-1131 Ext. 621, 627, or 628 Fax 847-688-3964