Keelboat Certification Question...
I''m a little confused in that I thought the Basic Keelboat certification was the lowest level (but I could be wrong). Basic Keelboat is a prereq for Coastal Cruising, which is a prereq for Bareboat Cruising.
Having completed all 3 levels in the past 6 months, I can tell you that there is a great deal of repetition of information. I like to believe that''s because the fundamentals of sailing, the rules of the road, weather, etc. are the same no matter what size boat you are on.
Where the 3 courses differ is in larger boat handling, docking, systems (plumbing, electrical, auxiliary engines, etc.). My opinion is that Bareboat is not that much more informative than Coastal. It does give you reinforcement of what you should already have learned, but on a much heavier boat (a 40'' vs. 30'' for example).
And another unsolicited opinion: the US Sailing certification series worked well for me; I thrive on structured, challenging instruction. To make it work for you, get in with a good school and try to get the most out of it you can. Nothing teaches like "doing." I skippered a 45'' boat in the BVIs last month as my first charter, and I really felt pretty well prepared and confident about it all.
Good luck and fair winds.