Basically not many if what you are asking about is the CG equivalent of the ROTC Scholarship. I believe that the only one that approximates an ROTC scholarship is the College Student Precommissioning Initiative. However that is a minority recruitment tool and is restricted to students at selected schools: http://www.gocoastguard.com/find-yo.../college-student-pre-commissioning-initiative
Additionally- with enlisted service in the USCG, you will earn both active duty and GI Bill educational benefits just as you do with any of the other services.
One avenue that would pay you some subsidies and allow you to commission into the USCG would be the MMR-SIP program at the Maritime Colleges. That program would pay you an annual Stipend and I believe will offer you in-state tuition rates at the state Maritime Colleges in return for taking Naval Science classes in school and accepting a reserve commission (USNR- MMR) after graduation- a requirement which would be satisfied though by commissioning in the USCG- additionally most of the state Maritime Academies have regional agreements that give instate or near instate tuition to many states not just their home state. You might want to look into this option if a USCG commission is your goal- especially if you have applied but not been appointed to USCGA or USMMA. They are colleges with regimental programs and a military lifestyle (less adversarial than VMI or the Citadel for example but definitely more so than a typical civilian college) that focus on sea going careers and all of them have a large number of graduates who go onto careers in the USCG.
Hope this helps- gives you some food for thought.