Not a fan of this answer ...

You've put a lot of effort into this! I found it to be exhausting to read everything and take the quizzes. I also thought some of the graphics could be less confusing. For instance, I find it confusing when a red dialog pops up when I select a correct answer. Red means wrong, right? Numbering the boat positions (which is a convention here) would help me quickly understand the scenario. Removing the mark and mark rounding arrow when they're not pertinent would help. Overall, I think that if your target audience is newbies, this may do more to scare them away than make them comfortable on the racecourse. For them, simplifying would help.

The title of the situation implies this occurs prior to the start. The side bar notes that RRS 17 may be in effect, but fails to discuss the limitations of Proper Course, being that there is no proper course prior to the starting signal.

Thanks for building and sharing!

I generally like this as a learning tool, but some of the situations could use more setup to guide the learner towards the specific rule being tested.

For example, I got this one wrong because it was not clear to me the question assumes yellow did not have time to change course / if blue does not change course they will collide. If "The move" had said "You hold your course, causing contact with yellow", that would have been a stronger setup, as it is impossible to infer if there is/is not still plenty of time for Yellow to change course using just the drawing.

Same thing happened in the section when it came to luffing rights. This situation's answer (and another before it) turns on how the overlap was established, but the setup does not tell you how the overlap was established.

This is as far as I've made it, but I'll definitely keep an eye on this. I've found rules-related questions put to AI to be answered ok for the basics, but replies are quite poor for tricky situations involving multiple rules. So Im curious if you verified all the situations/answers throughout the tool.

I too see the effort that has gone in. Good on you. If it were me, I’d try to stick to the common phrases used to describe things. How the forums experts word things here is a great example. I’d understand hesitancy to use complicated wording, as can be the case here, but I wouldn’t invent a new lot of wording instead. 
I’m not sure the relevance of the (0.5 boat length?)circles around the boats, they may confuse beginners into thinking there is some relevancy. 
Rule 12, ‘same tack, inline’, isn’t the right wording. 

‘The identical turn, and this time legal. Rule 16 does not forbid changing course; it requires that the other boat be left able to respond. Three lengths of water is room, and she has time to head up with you.’

I’d be careful about the expectations this sets. Would people leave expecting a boat less that 3 lengths to leeward to not change course? 

It’s the high level of nuance that makes this tricky. Keep at it!

I too see the effort that has gone in. Good on you. If it were me, I’d try to stick to the common phrases used to describe things. How the forums experts word things here is a great example. I’d understand hesitancy to use complicated wording, as can be the case here, but I wouldn’t invent a new lot of wording instead. 
I’m not sure the relevance of the (0.5 boat length?)circles around the boats, they may confuse beginners into thinking there is some relevancy. 
Rule 12, ‘same tack, inline’, isn’t the right wording. 

‘The identical turn, and this time legal. Rule 16 does not forbid changing course; it requires that the other boat be left able to respond. Three lengths of water is room, and she has time to head up with you.’

I’d be careful about the expectations this sets. Would people leave expecting a boat less that 3 lengths to leeward to not change course? 

It’s the high level of nuance that makes this tricky. Keep at it!