Guantanamo Bay

My son just got his orders, he is to report to Guantanamo Bay out of A school. He's a Master at Arms, and there is no little information on the base. My son and I are very close and this is hard on the both of us, but I support his decision to go into the Navy. 

From what I gather, the base is very isolated, no cell service, and bad internet. His rate for Master at Arms is "security forces". Does anyone have an idea of what he will be doing?

I read that marines do the fence line security, and the army and national guard are in the detention center. If I'm way off base, please let me know. He nor I know what he "may or may not" be doing in Gitmo. 

I hear that the barracks are 6 to a room, resembling a shipping container? Is this true? SO many questions... any advice about the base or words of wisdom?