Studying for any test using unlimited study material cannot be bad, if you can study to that level all other levels should be covered. A word of warning to those using " cook book" methods. That is, to those that study nav problems and don’t understand theory, There are questions on the USCG test where you have to reason the answer using knowledge based on theory. For instance, If you don’t understand the time diagram you need to learn it. And yes study, study and then study some more. Good luck.