How can you get in contact with someone not knowing their ship or division?

wait for a letter to come home

You have to wait for that letter from them

Check with recruiter or wait for a letter to come home. Also FB has a few great pages for family of recruits....etc.

Sailors get to write a letter home which also includes a letter from their commanding officer. This includes ship/division and address to mail letters back and their graduation date. We got this letter in a month of boot camp. So my bet is they are forced to send a letter home

You can call their recruiter and they should know or can if out for you