I agree with Wille's "Start Somewhere" comment. When I look at the mishaps, some fatal, that wouldn't've happened if people heard the "Don't Anchor From the Stern" message I know we've got to be helping when we do boater education. Occasionally we train people from other states. I tell them they should log onto their state's course, study the state-specific items, take that test, and get their home state's card. That's even though I request a FL card for them and most states reciprocate. I want them to know what THEIR state wants them to know. But there's a flaw. I've done essentially what you're talking about here. Go take another state's test and see what the score is. I could miss all the state-specific stuff and still pass because I can ace all the rest. So I could have a Louisiana card, for example, just for the fee and what I know about boating in general. The flaw is somewhat controlled when we do the one-day About Boating Safely program in FL. 80% is the overall passing score, and we'll give a participant a completion certificate at that score. BUT to get the FL Boater Ed Card, they must also have at least 80% (meaning no more than 2 wrong) on the 10 state-specific questions. Those on-line classes don't require that.
I think part of why FL asks the questions that they ask is to try to keep boaters FROM doing things that'd be violations. Then IF they violate, they can't claim ignorance. Not that ignorance is an excuse, but the officer can say "Hey you passed a test about this to get that card you showed me."
At the start of our class I hold up the ABS course book and tell the class "This is the book of things TO do." Then the FL book "This is the book of things NOT to do."