Tacking on a mark, room to keep clear?

However, it does not apply between boats on opposite tacks · Originally posted by mozzy

Originally posted by mozzy

So i guess you'd start with a basic rule that covers all situations of:"However, it does not apply between boats on opposite tacks"

But that alone would be too broad and would include boats on opposite tacks downwind (opposite 'gybe') and have unintended consequences for leeward / gybe marks. 

So they add 'on a beat to windward' to avoid the above.   

But adding that leaves a grey area for reaching legs that are ended with a tack. As these are not really a beat to windward, but you do end up with boats on opposite tacks at the mark. So they add 18.1 b) 'between boats on opposite tacks when the proper course at the mark for one but not both of them is to tack'... which covers the tiny instance after you've tacked to fetch around a mark you have reached toward on the opposite tack. But also seems to have a lot of duplicity with 18.1 a).

In the real world I see no reason why a boat clear ahead and on the same approach tack shouldn't be given room to round the mark ahead / inside, even if that includes a tack.

Without thinking too hard about it, I think a reason why is that while gybing is instantaneous (and all the stuff about mainsail filling in MR has just been put back there to maintain the pre 1995 status quo), tacking involves a significant change in speed and manoeuverability, which runs contrary to the 'orderliness' imposed by crystallising entitlements at the zone boundary.

But finding a way to word that without giving mark room to port tack approaches is hard.  I think some of the difficulty comes from 'tack' the verb not being defined. 

If the verb was defined as the time between head to wind and close hauled (as implied by rule 13), and room was given for that 'tacking' then you'd escape this ridiculous situation where a boat first entitled to mark room then right of way is the keep clear boat for 45 degrees of turn, despite that turn being completely predictable by all boats around. 

The definition of 'tacking' was removed from the rules in the 1995 rewrite.

If you wanted to convey the meaning you seek, then, in the few places it would be required you could say 'a boat, having passed head to wind but not yet reached a close hauled course'.

Generally, despite the habits of drafters to define labels for every damn phrase, unless a phrase is used frequently, that is, more than three or four times in a document, it is better not to create a defined term, but use the phrase when needed.