If the school is an accredited tech school like a community college you are on a good track for working shoreside. I can’t speak for New Jersey or that area but there are many diesel shops in the Fort Lauderdale area that specialize in marine propulsion and seem to always be looking for techs. Good mechanics are very hard to find and guys who like to work in the confines of an engine room are even more rare.
If you want to move on to working at sea your school time will be worth something, but in the new world order of training it is an open question as to how much time it will count towards CG certification. If you can leverage your Cat, DD, Cummins, and other diesel experience into a shop job with a workboat company you will be well on the way towards a good career at sea or onshore.
Your school should have a placement office and they must have info about local marine diesel shops looking for techs. Many of the guys I have met who took community college diesel courses were hired before they graduated. Try and concentrate your job search on the major service companies with a manufacturers affiliation and then try to get into the marine diesel side of the operation if you can. Next choice would be to go with the large local marine diesel shops … you want to have further training opportunities available, factory courses and such.
Good luck, there is a lot of opportunity for someone with a plan and the vision to make it happen.