So much depends on what his score is on the ASVAB test, which will drive what he'll be able to do, job-wise, in any of the services.
http://www.military.com/ASVAB
The Navy is not for everyone...but whatever he chooses, he'll learn a lot about life.
Lastly, make sure your son does his homework. The recruiter will not always have your sons best interest in mind.