Thanks for the reassurance! This is just making me nervous because he has truly worked so hard. The school he is attending is nationally ranked for its engineering programs and is known for being one of the most rigorous, especially for his specific areas of study (nuclear and mechanical engineering). Added to the mix is that the school has actually had 4 on campus suicides this semester alone and the university feels like it's in a dark place. I think he is doing pretty well over all (and I am able to see him often), but the whole situation is fairly anxiety inducing!
Looking at USNA over the past 3+ years via my DS and comparing to engineering programs I've either taught at, hired from, or advised as part of the ABET accreditation process (or have friends on faculty), I think your son is proving that academically he'll be successful at USNA. Everybody takes about the same classes the first two years of any engineering program (USNA included).