William Leckie US Navy

I am searching for information on my great-grand uncle William Leckie. I know that he served in the Navy sometime in the 1930's or 40's and I was told that he was a Lieutenant Commander. I know that after he left the Navy he became a professor at a University in Florida. I have tried to get his records from the National Archive, but I can not obtain a signature from him or his next of kin because I can not get in touch or locate any of them. If any body knows anything about his service, or if anyone can tell me how I can obtain his records please let me know, it will be greatly appreciated.