So this is rule 18.3:
Passing Head to Wind in the Zone
If a boat in the zone of a mark to be left to port passes head to wind from port to starboard tack and is then fetching the mark, she shall not cause a boat that has been on starboard tack since entering the zone to sail above close-hauled to avoid contact and she shall give mark-room if that boat becomes overlapped inside her. When this rule applies between boats, rule 18.2 does not apply between them.
This sorta like says: If I enter the zone on port tack, I am not allowed to disturb boats that entered the zone on starboard tack - not even if I entered the zone first. Not sure if that's fair, but at least it is easy to understand.
BUT
Why does this rule apply only to a port side passing? AFAICS the exact same thing can happen on a starboard side passing?
I can easily see myself entering the zone (first) on starboard tack, wanting to tack to port in order to pass the mark on starboard; Sounds easy, as I have right of way, but the minute I tack, I need to think of rule 11 and 15.
If I tack, I might get overlapped from behind on the inside. Then I have no rights what so ever? Isn't that just weird? Because I tacked in the zone, rule 18 is off - or is it? Anyway, It would not help me. I just need to keep clear. Even if I tack clearly ahead, those port tack boats may catch up and overlap on the inside; I'll then need to keep clear as stated by rule 11 and with no warning - by rule 15. Or is it just 18.2.a?
Something is fishy, but that's not all:
Rule 18 starts of by stating it does not apply to boats on separate tacks on an upwind beat. Still, rule 18.3 seems to apply to just that situation. So is rule 18.3 on or off? Turns out it is on, - the minute someone tacks and the two boats are on the same tack - rule 18 turns on..
What does that mean? Rule 12 is off when tacking in the zone, but only on a port side passing? Why not on a starboard passing? Why does that make sense?
Like... Is the inverse 18.3 correct for a starboard passing?
Try this:
If a boat in the zone of a mark to be left to starboard passes head to
wind from starboard to port tack and is then fetching the mark, she MAY cause a boat that has been on PORT tack since entering
the zone to sail above close-hauled to avoid contact and she shall NOT give
mark-room if that boat becomes overlapped inside her. When this rule
applies between boats, rule 18.2 does not apply between them.
Naah, that does not make sense.
So 18.3 is there to favour those starboard boats already in favour? Why?