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!

Thank you all! I really appreciate your time and your expertise! You are all rockstars and so supportive! Every one of you found something real, and two of you found things that were plainly wrong rather than merely unclear. 

Here is what has changed.

Positions are numbered now. 1, 2, 3 down each boat's track, and the same number on both boats is the same moment. Mike was right that this is the convention and right that its absence was costing readers — this also helps learners get familiar with the notation used by convention. I did not adopt the L/W/P/S naming convention, because most of the questions are asking students to figure out just that, or to reinforce that muscle memory.

Marks only appear where a rule reads one. They used to appear on every card as camouflage, so that a mark could never give away a rule 17 question. But removing irrelevant information for clarity is the right choice.

The cards now state what the picture cannot show. This was the heart of several of the responses. Whether the other boat had time to respond, and whether it had become clear she was not keeping clear, are judgements about seconds and conditions. A static diagram cannot carry them, and asking a reader to infer them from hull spacing isn't fair and is confusing. So the setup says it, the way a question states its relevant facts before its diagram. A rule 14 card now reads "You hold your course, and Yellow holds hers. She is not keeping clear, and you are going to hit her" — and the question left is the rules question. Section B has been the one I've found hardest to structure for learning, because rules 14, 15, 16 and 17 are almost always in play in combination, but a student needs to learn what each one is and when it applies before understanding how they commonly stack. Continued pressure from this community of experts, with good experience working with newbies, is very helpful!

And the cards now say how the overlap began: Daniel put his finger on something I had simply been assuming: two boats drawn overlapped might have been alongside all leg or might have come through from clear astern a moment before the drawing starts, and rule 17 turns on which. Nothing in the picture could tell you. Every same-tack card now says, in the setup, whether she came from clear astern within two of her hull lengths.

- The app told you rule 18 "has nothing to say yet" at a starting mark. It never has anything to say there. The code knew the Section C preamble and was failing to reach it, because of which end of the line the boats happened to be nearer.

- Rule 17 was being switched off as soon as two boats opened past two hull lengths. The two lengths are a test at the moment the overlap begins, not a leash — Case 7 puts it as "was within two of her hull lengths of W when the overlap began", and in that case the two sail alongside for 120 yards with rule 17 in force throughout. Fixed.

Smaller things: red panels no longer appear under correct answers (Mike, you were right — there was a BUG!); the reveal is materially shorter; the rule question is now asked on many cards where the move was legal, not only on fouls; and the Sandbox feature is hidden until there is a real need for it — it wasn't ready for prime time.

Word choice — more work to do. Words are hard! Trying to bridge the highly defined specialized terms (and caveats) in the rule book to simple but sufficiently precise language that a newbie won't be intimidated or confused by is hard. I've tried to thread this needle by using a simplified term but linking out to the full definition from the RRS where it's tricky. As you see a phrase that doesn't seem right, just point it out and offer a suggestion that you think would work better. I'm happy to crowdsource from this group's experience.