Great insights on scoring inquiries! I had a situation last season where a protest led to some serious confusion. Clear communication is key in resolving those disputes. Thanks for highlighting this!
https://www.racingrulesofsailing.org/posts/1 geometry dash

I think the start/finish line being considered an obstruction on a downwind leg can be a bit tricky. It really depends on the specific circumstances and the interpretation of the rules in that situation. From my understanding, if you're sailing downwind and need to avoid the line or it blocks your route, it could be treated as an obstruction. But it’s also important to remember that the line itself is a defined part of the course, and unless there's a clear reason to call it an obstruction, it might not apply in every case. Always good to check the race instructions and any specific local rules.
https://www.racingrulesofsailing.org/posts/1 hot games

Below are the trapezoid courses of the most recent Princess Sofia regatta.   Unlike the ILCA trapezoids,  here mark 3s ( there is no gate) is no longer in play as the boat sail to the finish line.  I recall that during Perth 2011 we pulled the 3s mark.

I will attemp a guide next week, at an event at the moment. 

Ben,

1. I enclose an extract of relevant portion of Case 50.

A starboard-tack boat in such circumstances need not hold her course so as to

she does so she will break rule 14.

The fact that L took action to avoid collision at a time when W also initiated action implies there was an apprehension in the mind of L. W, as per me, took the action late.

2.  Case 50 does not say anywhere that it can be applied to rule 11.