Isn’t #8 kind of essential? If you’re on the water, you gotta know how to swim.
Even #9 - there’s a lot of boat collisions that happen because some novice doesn’t know who has “right of way” when boats approach, and a game of chicken results
Which means that the other guy is not an expert, because an expert sailor always presumes that the other guy is clueless, doesn't see him and will turn towards at the worst possible moment in violation of all rules, procedures and common sense.