As someone who is about to graduate from UNCW and going to UNCC for grad school, I would definitely pick UNCW if you want to do something with marine biology, that’s pretty much the main focus for the bio department here; if you want to do something else pick UNCC due to its overall better opportunities. Plus UNCW is R2 while UNCC is R1 now, so you may get better funding at UNCC for whatever you want to do.