There are colleges in the Philadelphia area that have some marine science classes. (I'm not sure if you go to school in the area or not...) Temple University has marine biology courses including field courses. Drexel University has marine ecology courses. Some colleges have very specialized majors in Marine Biology if you were sure that's what you want to study. You might have to transfer from your current university if your school does not have the major that you want.
U of Delaware has a marine science major: https://www.udel.edu/apply/undergraduate-admissions/major-finder/marine-science/
Here is an opportunity to be a "guest student" at one of the best oceanographic institutes in the country: https://www.whoi.edu/what-we-do/educate/gueststudent/
There may also be volunteer opportunities if you wanted to learn more about this field before making final decisions:
Hope this helps!