Boy, GPA's have come up at NPS.
Granted, it's been a while since I was at prototype (1999), but generally, good evals were saved for the fleet sailors. Meaning, even the best students got only marginal evals by fleet standards. The easiest way to become an officer is either STA-21 or getting picked-up for the academy. Didn't seem like either one was very difficult, 'specially if you're willing to go submarines. We had a quite a few go these routes, the only requirement seemed to be a go Navy attitude. They picked up guys at E-4 as much as E-5.