A fellow judge send me a couple of TSS diagrams with rule 18 situations. This one is a representation from the slide with case 3 in the Rule 18 Workshop you can find under FILES. When I looked at it, I got caught by the fact that Yellow also could be at fault...
Here's the diagram - I changed it slightly to make the point - animated and static:
These are the facts:
Yellow entered the 2 length zone windward and overlapped with Blue on starboard tack. Windward mark was to left to starboard. Blue went head to wind, Yellow had room between the mark and Blue. Yellow changed course abruptly and her stern hit Blue starboard side. There was no damage and Yellow tacked around the mark.
Now here's my question: If Yellow just did a normal tack, you would disqualify Blue for not giving enough room as the outside boat (RRS 18.2(a)), but what if Yellow changed course so abruptly that contact occurred, which would not have happened if Yellow would have tacked normally? Under which rule would or could you disqualify her? Or is Yellow free to do as she pleases?
Please give me your view by using the comments.