Has Yellow finished correctly? She hits the finish mark as she finishes, so she needs to take a penalty turn and cross from the course side. She gybes to port and rounds up, passes HTW and then crosses the line before reaching a close hauled course. So has Yellow completed her penalty turn?

I have written a new short article on what constitutes a tack. It is on my web site near the bottom of the home page - see Appendix D What constitutes a Tack

https://sites.google.com/site/johnsrcsailingrulesandtactics/

John

In a similar vein, a yacht tacking from port to starboard does not gain starboard tack rights until her sails are full on the new tack. In my opinion, if the port tack vessel has to start an evasive manoeuvre before the starboard tack yacht's sails are full, then the tacking yacht has broken Ruel 13. Unfortunately I seem to be in a minority on this point as yachts to leeward and slightly ahead on port think they can tack with impunity and yell starboard as they come head to wind,

Or they will generously warn you that they are "Tacking", as if that absolves them of the fact that they are tacking in your water or into you!