Hammer the SAT and ACT as a Junior
Was that you first sitting for the SAT? If so, you haven't done yourself any favors. I strongly recommend taking both the SAT and ACT at least twice during you junior year. Get some good scores on the books before June of you Junior year. That way you can also make the first ROTC boards. Having early scores on the books is also essential for MOC nomination packages for the SA's with deadlines in early September (i.e. now too late for the class of 2017).
With reguard to the USCGA, the first early decision deadline is 10/15! Your scores might be back in time for the regular admission review process. Earlier is always better. Remember, the USCGA is only going to take about 250 first year students this fall. About 50 will come from prep school. The rest of us are competing for just 200 slots.
To all you freshman and sophomores out there -- if you're not studying and planning to shine on SAT and ACT exams NOW, you're going to be too late. If you're a HS Junior, schedule and take both exams at least twice -- the last no later than spring break of your Junior year. There is NO testing over the summer!