I'll just add too that Cortramid/ Summer Cruises and per an earlier note from someone else NSI this year were not guarantees for NROTC national scholarship winners. Well, NSI at SMCs is seen as redundant and I believe most incoming there don't attend NSI anyway. But reports came from all 3 not having the experience they expected. This year a number of midshipmen designated themselves to return to NSI as an instructor, or :"chose" to go on a specific summer cruise, and then ended up going - nowhere. It was pretty awkward as my DS went on a dream cruise but a number of his buddies kept waiting for the phone to ring, and it just didn't.
So the key word you may wish to find if you're planning on taking summer courses is "Asynchronous" since maybe he can take a course, slam through the modules online to allow himself the window he needs for summer training.
Good luck.