The key words from that are "just short of his 18th birthday." Was he completly through puberty, or did he experience further physical growth while at Annapolis? 6' and 118 lbs suggests he probably filled out a little in one or both while attending the USNA.

[OTOH, I was 5'5-1/2" and 120# at my boot camp physical, and 5'5-1/2" and 145# when I graduated. {And 5'5-1/2" and never-you-mind today.}]

I'd guess that he put on weight but not height, but that's just a guess based on my experience. I was 5' 10" and 125 lbs. when I went to basic. I gained twenty pounds by the time I graduated because, even though I was exercising a lot, the Army fed me more than I'd ever had before. I was still the same height. I'm actually shorter now than I was then, a common product of getting old, apparently.

Amazon's "Search inside the book" feature does the same thing, and it's often a different set of pages. So if what you are looking for is unavailable in one, try the other.