BLUF: You are joining the nuclear Navy for the wrong reasons based on your post. If your passion is physics, then finish your degree. There is nothing wrong with that path.
Enlisting post-grad is probably not a wise decision for you, either. There are shelf-lives on technical degrees and 6-8 years spent plugging leads into 1980s-era server cabinets or greasing various parts of an engineroom is not going to keep that knowledge sharp.
I appreciate everyone's feedback, it certainly is informative. One quick question, how do the online/carrier/submarine classes work? Forgive me if it's been addressed already, I am currently searching through all resources. Thanks in advance.
Submarines:
There are no classes. It's entirely self-study. You at most will be allowed to take 1 or 2 PACE courses. I don't know if they'll have Optics 304 or whatever it is that Physics majors need to take to graduate; all I've ever seen a Sailor take is 100/200 level courses and I've never seen anyone get better than a C. Most end up asking the XO to waste the Navy's money and cancel the course.
Your only time to take them is going to be deployment, at least on an SSN. That's 6 out of every 18 months. During workups you will be far too busy with drills, admin, training, etc. to be able to handle classwork. During extended drydock periods the nukes are still very busy setting plant conditions for shipyard bubbas.
Few people on the boat will be supportive of your college classwork. They would rather you work on further qualifications -- EWS, Quality Assurance quals, etc. Big Navy doesn't care about your college classwork as an enlisted Sailor either; Big Navy wants you to qualify EWS, reenlist, make Chief, and Serve as LPO at sea. At which point Big Navy wants you to qualify EDMC, make senior chief, and be an EDMC somewhere.
Let me put it this way:
You're MM2 EarthDecon on a patrol and you've just gotten off your 6 hours of watch. You eat for 30 min. You do your 1 hour of after-watch cleanup. Then you have Eng Dept training for an hour. Then you have divisional training for an hour (on days that you don't do this, substitute post-watch preventative maintenance or monitored evolutions). Because the Dept did poorly on LOK on the last ORSE, you also have mandatory eng dept self study for an hour. You now have 6.5-7 hours before you are woken up for your next watch.
Tomorrow you will be up for 20 hours straight because drills are planned during your oncoming time and you got selected to be a drill monitor; the brief starts 4 hours into your off-going so as not to interfere with the meal, so even if you weren't hot-racking you'd be able to only get about 2 hours down tops.
Do you A) do your physics HW or B) go to the rack?
And that is why your plan to do college coursework at sea is stupid. Your opportunity to seek higher education as an enlisted nuke is either post-EAOS with the GI bill or via STA-21, the latter is highly competitive and largely based on your evaluations as a Sailor.
PS: That was the easy deployment schedule I referred to.