The situation is a mixed HC fleet, where a 20ft boat and a 40ft boat are approaching a mark, with the 20ft boat traveling faster and breaking an overlap near the mark.
The longer boat argues the zone began at 120 ft and the boats were overlapped when entering the zone, the shorter boat argues the zone began at 60 ft and the overlap was broken before entering the zone.
Definition state that the Zone is "The area around a mark within a distance of three hull lengths of the boat nearer to it."
A strict reading of the definition suggests the zone begins 60ft from the mark and that's when Rule 18 switches on.
But if the boats were even, or if the longer boat were slightly ahead, would the Zone be from 120 ft?
A prudent race committee will want to resolve the ambiguity in advance, wither through reference to a case, or through local practice, but the question is how?
RRS 86.1 doesn't appear to permit an SI to be written to change the definition of Zone, but perhaps allows a changes to 18.1(a) or 18.2(a).
Any recommendations, please?
If the 40 ft boat reaches the 120 ft zone, overlapped, but before the 20 ft boat, then she is the first of two boats to reach the zone, RRS 18.2(a)(1) applies and whichever boat is outside is required to give the inside boat mark-room, and RRS 18.2(a) last sentence applies
When a boat is required to give mark-room by this rule, she shall continue to do so for as long as this rule applies, even if later an overlap is broken or a new overlap begins.
If the 20 ft boat then becomes advanced and nearer the mark, then, theoretically the zone contracts to 60 ft, but this does not change the entitlement of the boat, overlapped inside at the 120 ft zone, to mark-room.
If the 20 ft boat becomes advanced and nearer the mark at the 120 ft mark, then the zone is defined by her length, as 60 ft, and at that point neither boat is in the zone and RRS 18 does not apply.
If the bows of the boats were level at the 120 ft zone, the protest committee would apply the last point of certainty: Immediately before the 120 ft zone boundary, the bow of the 20 ft boat, overtaking from astern was further from the mark than the bow of the 40 ft boat, so the 40 ft boat was nearer the mark and the 120 ft zone would apply.
There us nothing for a prudent race committee to resolve.
This is a straightforward application of the Definition of zone, RRS 28, and the last point of certainty principle.
Is it possible that because the 120 ft zone is behind them, it can never be the defining zone i.e. once they have passed the 120 ft zone with the 20 boat closer to it at that point in time, the zone will always be the 60 ft zone no matter which boat is nearer to the mark?
I suspect that this is one of those situations where the rule writers would have decided that it wasn't worth the effort to resolve this in the rule in order to keep it simple. After all, neither boat wants to get tangled up with the other boat. The outside boat will likely just give the inside boat room.
I suppose when 40 gets bow out between 60 and 120, the zone leaps back to 120 and you could backtrack to that zone, where 20 was nearer the mark: I think that's looking a bit absurd and convoluted.''
I haven't squeezed the lemon dry, but I suspect that you're right: no matter what, the outside overlapped boat is going to be required to give mark-room, so it's not worth chasing after the corner cases.
It's possible, but I think it would take a Case to do it, otherwise, I think applying the words of Definition Zone causes the 'leap-over'.
This is where you want the sailors to focus on what is important, which is not to be stuck on the outside of another boat and to get into an orderly line so that you have all your options open after the rounding.
Paul, RRS 18.2(3) doesn't exactly get us there. It is a specific application of the Last Point of Certainty Principle that applies when there is doubt about whether or not boats are overlapped.
The more general statement of the Last Point of Certainty Principle is in RRS C2.6
LAST POINT OF CERTAINTY
The umpires will assume that the state of a boat, or her relationship to another boat, has not changed, until they are certain that it has changed.
This is an important principle: judges use it all the time where there is doubt.
I'm a bit amazed that it is not discussed in the Judges Manual
Thank you all.