Boris,

One boat is clear astern of another when her hull and equipment in normal position are behind a line abeam from the aftermost point of the other boat's hull and equipment in normal position. They overlap when neither is clear astern.

Neither boat is clear astern

These terms always apply to boats on the same tack. They apply to boats on opposite tacks only when rule 18 applies between them or when both boats are sailing more than ninety degrees from the true wind.

One of the 2 boats is sailing less than 90 degs from the true wind, so we check if 18 applies ...

Rule 18 does not apply .. [RRS18.1(b)] between boats on opposite tacks when the proper course at the mark for one but not both of them is to tack.

It is not G's proper-course to tack at the mark as the STB layline to the next mark is above the mark shown. Likewise, it is not B's proper-course to tack at the mark.

Since G is more than 90 degs from the TW, and looking at Case 132, it'd be hard to argue that G is on a beat to windward. Based on both of those, G is not on a beat to windward. Therefore 18.1(a) doesn't turn-off 18 either.

Rule 18 therefore applies.
Therefore one of the opposite-tack requirements in the definition for "overlap" applies.
Therefore the term "overlap" can be applied to these boats.

(Note: You should look at the previous thread discussing a similar situation when a windshift puts the offset mark further to windward than the windward mark)
(Note: This is the same situation as a port boat reaching in at the pin-end in a windward finish ... your previous post .. where the mark is being passed and not rounded).
(Note: This situation is true at a passing mark like above, a port-pin finish mark, and a port-rounding leeward-mark where the boats sailed/were-swept past it.)

Ang

Looking at the diagram, one could argue strongly that the proper course for G is to tack at the mark, as STBD tack seems heavily favoured. Assuming B to be close-hauled, the direction to the next mark is only about 10-15 degrees above that course. Pt tack therefore about 70 degrees off.
Ant

Ant said ..

one could argue strongly that the proper course for G is to tack at the mark, as STBD tack seems heavily favoured

It's just over 15 degs above the close-hauled course.

To support your position Ant, I would argue that .. assuming that there isn't a persistent veer going on, that tacking at the mark or waiting for the layline .. that both of those are equally proper courses as they would get the boat to the next mark at the same time.

So .. arguing with you (and against myself) going to windward G has 2 proper courses, close-hauled on port and close-hauled on stb and that she is free to flip between the 2 of them.

If I wanted to get picky .. and poke from the other side .. I'd say that tacking at the pin will add 2 tacks to her leg .. and depending if the leg is long or short .. those 2 tacks certainly won't get her there faster than not taking those 2 tacks.

I think it would depend on how close the next mark is. If it's only 10-20 BL's away, then it wouldn't be her proper course to put those 2 tacks in.

It's all a mess .. along with the other scenarios that this exact issue arises.

Ang

I think everyone would agree that the answer to the question of whether or not an overlap exists turns on the point of whether or not G's proper course at the mark is to tack. If it is then rule 18 does not apply (see 18.1(b)). If 18 does not apply then the boats on opposite tacks are not overlapped and the situation is governed by rule 10 unless G tacks in which case it would be rule 13. In either case if G holds her course she is likely to break one or other of these rules.
Whether or not tacking is G's proper course depends entirely on the judgement call as to whether or not she would have done so in the absence of B - see definition of Proper Course. In considering this a PC would consider what other boats had done, what G may have done on previous laps and just apply common sense. If the next mark were only a short distance G might argue that she would sail on to the lay line but if it were some way off then tacking at the mark would seem the most likely proper course.
Even if it were decided that tacking was not G's proper course it would not do her much good. As inside overlapped boat she is entitled to mark room which is room the leave the mark on the required side - see definition of Mark Room. That would mean that she would only be protected against a rule 10 infringement until she has passed (stern cleared abeam) the mark. If she tacked she would lose any protection for breaking rule 13 as mark room in these circumstances does not include room to tack. G would gaim protection under rule rule 18 for the couple of seconds it took here to pass the mark - a very high risk strategy.

Also have a look at rule 18.3

That would mean that she would only be protected against a rule 10 infringement until she has passed (stern cleared abeam) the mark.

Even earlier there may be turn off of rule 18 by rule 18.1(a) - when Green will come on the close-hauled.

Even if starboard tack were the favored tack to the next mark, a proper course for G would be to round up to close-hauled on port tack to maintain speed, and then do a standard tack.
A U-turn from a broad reach through a tack to close-hauled would be a speed killer - and therefore not G's proper course to finish in the fastest time, disregarding the other boat.

The following post is purely a invitation to the many thoughtful contributors on the Forum to blow holes in an idea I have and to engage in a dialog.

This issue of what happens at a windward passing-mark to port with boats on opposite tack has come up now 3-4 times in different scenarios. It's clear that the combination of 18.1(a), (b) and Case 132 create a level of uncertainty and indeterminability which won't stand long. Surely the Rules Committee is working the issue.

That said, being cursed with an engineer's brain, I can't help but work a design-problem once the seed in embedded.

So .. I've thought quite a bit about the different scenarios where this problem arises .. which all have, at different times, been described in separate scenarios/questions on the forum.

1. Boats on opposite tacks, in the zone, at a port-pin on the finish-line to windward
2. Boats on opposite tacks, in the zone, at a port passing mark (i.e the next mark is windward of the starboard-tack close-hauled-course from the port passing-mark)

Following is what I believe is a solution to this issue. I believe in elegant solutions, so I went though a couple iterations to simplify and reduce to the minimum that accomplishes the goal. I think the issue shown by the above scenarios can be solved by changing RRS 18.1(a) in the following way:

18.1(a) between boats on opposite tacks on a beat to windward where the starboard-tack boat is on a beat to windward.

I've reached my limit in challenging my own idea, so I'm asking anyone who is willing to engage me on this to do so. I can't see where this doesn't "fix" the issue ... i.e. that at the scenarios that we've been discussing, that it's always clear that Port DOES NOT get mark-room .. and that it's relatively easy for boats on the water to determine who has what rights.

Also, I can't see an instance where this creates a new problem in attempting to fix a different one.

It's a sincere request for criticism.

Ang

Hi Angelo

Sorry Boris, you'll need to be more clear in what you are trying to say as It's not clear to me. Walk me through step by step what you are trying to say in the drawing. - Ang

I believe Boris is suggesting that in position 1 Yellow is close-hauled and therefore on a beat to windward, but in position 2 she is not, due to a wind shift.
The problem remains that "on a beat to windward" is undefined in RRS and in your proposal.

On a starboard hand leeward mark blue is running on port. Yellow has been carried past the mark in the tide and is sailing back to it, or alternatively yellow is sailing on a different course that requires the mark to be left to starboard. Under your rule change if yellow approaches on a beat blue is not entitled to mark room but if she approaches on a close reach blue is entitled to mark room. It still requires blue to judge yellows point of sailing to know whether or not she is entitled to mark room,

Phillip, in regards to Boris's diagram and your explanation.

Since there is no finish line drawn, we'll assume that this is a passing mark scenario .. and therefore the next mark is further to windward.

When Blue first enters at 1, based upon my change, 18 is off because as you said STB is on a beat, RRS 10 controls the situation. As the wind lifts Yellow, she is trying to get to windward and on a beat and would naturally follow the wind up in the lift, staying on wind.

Yes, my "change" does not allow Yellow to bear off to the mark to pinch off Blue (port).

That said, RRS 16 still applies just as if the mark wasn't there and if Blue was clearing Yellow ahead, Yellow is restricted to how and when she comes-up with the wind to the point she gives Blue opportunity to keep clear.

Ang

Good one Bill .. that looks like an example where my change opens-up an issue that didn't exist before (as compared to Boris' where the current Rule has an issue as well).

We should assume that both Yellows were swept through or past the zone as well or as you said sailing from a different direction and thus entering the zone as your show.. since if they entered the zone clear ahead of Blue and stayed in the zone (sailing the same course and coming from the same direction as Blue), 18 would have stayed on for Yellow by 18.2(b)-(c) (though an 18.2(d) discussion that Yellow was given mark room when she first entered the zone might be interesting).

I agree, this is a new undesired consequence and abiguity created by my 18.1.(a) change (i.e. .. creates a new problem while trying to fix a different one).

Great new scenario to bound and the describe the issue. Thanks.

Ang