I'll throw in my 2 cents here.
No, you can't vape in boot camp. You can't have any personal belongings, aside from family photos, letters from home, and the like. Your first day at boot camp you strip down naked, put on your new pt uniform, and mail your belongings home. You have a shoebox sized locked drawer for your important items (which will be issued to you) that is randomly and regularly searched.
So no. The purpose of bootcamp is to tear you down and build you back up. It's an intentionally hostile and degrading environment, where you have no control over what you do or how to think. There is no opportunity for privacy and you have no rights. This goes on non stop for 2 months give or take.
Now off topic a little.
I was a pack a day smoker for close to ten years when I joined. Not once did I crave a cigarette once I got there, you just don't have the luxury of the time to. Once I got out I kept smoke free for over 2 years, then had a breakdown where I was smoking black and milds, got really sick after a few weeks of doing that, and turned to vaping as a solution back around April this year. I've not even thought about going back.