Could imagine me on the umps boat. Black on starboard luffs up because yellow is near on port (black wouldn't have luffed if yellow was ducking), yellow luffs up fraction of a second later, both apparently have no rights while luffed, black first out of luff still on starboard, yellow comes out of luff fraction of a second later still on port instead of completing tack which would have avoided collision, still on port collides with black, black penalised. I assess the Corinthian part of the sport I am watching and swim to the beach