What is he wanting to do?
I was in the Navy and Reserves from 1986 to 1996, and got to see quite a bit of the Pacific Rim, plus a few other
world garden spots like Panama and Ecuador. I was in a land based Patrol Squadron though, so at the end of the day, I went home to my apartment when at home, and back to a nice barracks room on an USAF base while deployed (while collecting Per Diem).
By contrast, my brother who served on submarines, while at sea shared a bunk with another guy (opposite duty schedules, one would be on duty while the other slept) and had a barracks room while in port. Eventually he and a friend got an apartment.
There was a pretty good discussion on military service in another forum a while back,
Here. It is worth reading.
If he really wants to join the military, (and not necessarily serve in combat) I would also look at the Air Force and even the Coast Guard, they all have good and bad points.
Navy:
+ See more of the world
- Live on a boat most of the time (minimal privacy), bases have less amenities than USAF.
Coast Guard
+ Normally smaller duty stations, Less time at sea than USN, possibly more interesting than USN
- smaller, maybe harder to get in to, probably see less of the world.
Air Force
+ Much better facilities at Air Force bases world wide. Better gyms, better food, better clubs, better golf courses, better base exchanges, better barracks.
- They need better facilities because in a lot of places, there is nothing else to do. There is some luck involved in assignments, depending on availability. Possible duty stations range from Really good, to Really bad, and everything in between:
http://en.wikipedia.org/wiki/List_of_United_States_Air_Force_installations
Just some random thoughts.
Tom