As for that video, ... who wants to walk through the rules and obligations?
Rule 10. Oh, and rule 14 too. Port was obligated to keep clear and did not. Port was obligated to avoid contact and did not. It was not reasonably possible for S to avoid contact, so she did not break any rules.
I disagree with S not being reasonably possible to avoid contact. They made virtually no attempt to alter course - they waggled a little bit, then t-boned P directly amidships. Deer in the headlights. They could have headed up, just as the boat behind them did (and avoided the situation entirely). Their spinnaker was only 1/2 way up when the collision happened, so that wasn't preventing them from luffing up.
Re: the boat scenario diagram - I knew you put that together quickly, so don't take my criticism personally - I just wanted to point out that even "pretty" diagrams can be misleading. You have to really think about what you're looking at and decide if it makes sense.
