+1 to NJROTC-CC. I've never heard of a school with NROTC that didn't have a Marine Option program. Each unit has a Marine Officer Instructor and Asst. MOI assigned who are both active duty Marines. When he applies NROTC he must select either the Navy Option or Marine Option. He cannot choose both.
No reason to not start working on that Marine PFT, which you can find online, in any case.
DS wanted to enlist with some of his buddies but Mom insisted on college first and going in as an officer. He acquiesced, loved the program, and is loving his life as a Marine Officer today. Maybe show your son the enlisted vs officer pay scales. Also, tell him it doesn't hurt to pursue NROTC as an option while he's still in high school so he can make an informed decision either way. Meet with the MOI if at all possible while visiting colleges. If you start doing that this spring, if not earlier, maybe you can encourage more interest in the NROTC path.
BTW - my kid started without a scholarship but had earned one by the second semester of his sophomore year.
(cross-posted with the inimitable AROTC-dad)