If your son sits waiting passively for something interesting to happen, well, short of a war, he'll be painting rocks outside the mess hall for the Sergeant Major until the day he musters out.
He needs to show some initiative. Find some project that matches his skills and interests, and then trick an officer into ordering him to do that thing every day while the others are disassembling and reassembling their bunks. Is there a vintage military truck sitting next to the motor pool, that could be painted and restored? A unit history to be written, with the Colonel's name on it? He sounds like he has some imagination and basic skills of connivery. Let him use them.
csb: When my unit went to Italy, my Captain somehow got the impression that I spoke Italian. He wanted the troops (mostly coming off Desert Storm) to have some downtime they could enjoy, in Italy. But they didn't speak any Italian, didn't know how the trains and buses worked. I got myself ORDERED to travel the local area, all day, in trains and buses. I wrote down my findings on a note card plus useful phrases, and next day took 5 Sergeants with me to do all the same things, including hitting the same bars. Then with their own note cards, they each took a group of soldiers around. This was all done under orders and while getting paid.