STUDENT FAQ and SUPPORT (no login required - your answer will be emailed to you)

Yes. 

As long as you are logged in, the system is smart enough to know what you have bought and gives you the appropriate credit automatically.

For example, if you want to now upgrade from Skipper Rank courses purchased last year to Bareboat Charter Master Rank courses now, you will be given the appropriate credit for the amount that you paid for Skipper Rank.