The link below may be of interest:
http://www.nrotc.navy.mil/scholarship_criteria.html
For context, USNA mids service select submarine warfare out of a variety of engineering majors, as well as pure science and liberal arts. All get a B.S. degree because of core courses in engineering and the sciences. See link:
https://www.usna.edu/Academics/Majors-and-Courses/
Of course, NROTC guidance rules in your case.
The key is if you want to be an engineering major of some kind other than nuclear, and that Navy likes, that's perfectly fine, if you have an interest in one. The Navy wants to see that you have the brainpower to master an engineering discipline that will form a good foundation for post-commissioning training in the roughly two-year nuclear power pipeline. Excel in your major, excel professionally as a mid, express interest early, and the path to subs gets firmed up.
The Nuclear Power School in Charleston is the first pit stop, where new ensigns from every commissioning source are taught Navy nuclear engineering from the ground up. Those ensigns have a wide variety of majors, I would suspect predominantly engineering of some type, but all have in common proven STEM skills and strong undergraduate academics. Then there is a stint at "prototype," and other schools as noted below.
Take a look at this:
http://www.public.navy.mil/bupers-n...iting brief with faculty slides (20NOV07).pdf
It's an older ref, but the bits about the training pipeline still apply. I am on the fly on my phone, but if you do some digging, I am sure you can find more current on "Navy Officer Nuclear Propulsion Training."
Of the many USNA midshipmen we have sponsored over the years who have gone subs, they have majored in: Mech E (a lot), EE, Systems E, Ocean E, Aero (thought they might want pilot, changed mind to subs), and some Nuke, etc. There were also a handful who majored in pure science or something like History, but as noted above, USNA gives everyone a good dose of STEM, enough to prepare any grad for the nuke pipeline.
Bottom line, IMPO, if there's an engineering major you prefer and the Navy says it likes, why not choose one you will enjoy? That makes working harder to get the top grades easier. You have flexibility here. You will be an attractive sub candidate if you are clearly delivering top grades, not struggling with STEM courses, and developing good leadership and professional skills through ROTC training.
