WTG and yes when you attend his graduation it is something to behold. When I graduated from boot camp at Parris Island my parents were not able to attend but my uncle who was in the Army at the time made a special trip down. Funny part is when he showed up he was in uniform and before I got a handshake from him, I had to salute him, he was a 1st Lt. at the time. He said he has gone to many a graduation and he is thrilled everytime he goes to one. But the feeling from your sons point of view is going to be memorable.
Give him a hearty handshake from me and tell him thank you from a former Marine, I am proud of him and i don't even know him personally except from here.
LawnDart