Can't believe there's only two Coasties on here... It would be worth it to talk to a Coast Guard recruiter. WAY more room on our cutters than Navy ships (I'm currently stationed on a 179 PC we're leasing from the Navy). As an E-4 (or under depending on the command), you could get qualified as a small boat coxswain and you're in charge of the boat underway. You'd probably come in as E-3 and get to work with the different rates (jobs) before you decide which one you like rather than get stuck with one upon signing your contract. Our bigger cutters go overseas and get some pretty cool port calls.
I know money is a factor, but the good thing is I make the same as an E-5 in any other service.
Also, I agree with everyone else, finish school first. Then you can use your GI Bill for grad school...