What defintions are you referrring to? The definition of "tack" is "A boat is on a tack, starboard or port, corresponding to her windward side." Blue is on starboard tack and yellow is on port tack. Nothing in the defintion turns on where the sails are or how they are filled.

Please refer to the definition of Leeward and Windward

A boat's leeward side is the side that is or, when she is head to wind, was away from the wind.  However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies.  The other side is her windward side.  When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat.  The other is the windward boat.

But what about this line in the definition:
"However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies." 

Since no boat has a ROW (or entitled to a room or mark-room),  so from rule 14 ONLY the first sentence refers to them. Both boats had a reasonable opportunity to avoid contact but did not it. So both should be disqualified for breaking the rule 14.

But both boats tried to avoid contact when it became apparent the other was not keeping clear.  Doesn’t that satisfy Rule 14(a)?

Rule 14(a) does not apply to them as they has not ROW.

How strange that the defintion reverses windward and leeward. What is the benefit of doing that?
The definition of Leeward and windward makes both boats windward boat with respect to the other  on the same tack. Once they become overlapped, are they both the give way boat under Rule 11? The definiton of overlap includes "They overlap when neither is clear astern". Neither was clear astern.  So were they at all times overlapped on the same tack both as windward boat and thus required to keep clear of each other?

Aren't we looking at something that is not very realistic at the 1st place, yellow wouldn't be sailing this angle on this tack for several minutes resulting in a situation rules aren't made for...?

Yann, This is not that unrealistic on Lasers. The upwind boat points pretty high, especially in flat watter, and the downwind boat typically sails by the lee, especially to stay on starboard tack

Yes lasers going down wind do sail like this in light air, with the main so far out that the boom is forward of 90 degrees to the CL of the boat.

This was discussed at great length here:
https://www.racingrulesofsailing.org/posts/214-what-about-this
The rules gurus conceded that the rules do not cover this adequately.

Lasers and other cat-rigged boats do sail by the lee at great extremes.
In my experience they will do so highly unpredictably, which I consider a significant factor absolving the boat on a beat.
"Last known position: serpentine."

I tend to agree with Boris, the only rule that either boat broke is 14. Either or both could have avoided contact by turning to starboard, and neither were ROW or entitled to room so neither is exonerated. 

DSQ both. 

Offset or spreader marks help to keep the boats apart to make this situation less likely.

This is a classic scenario.

Per the definitions both boats are "leeward" boats as they are on the same tack, overlapped, and on the other boat's leeward side.

What about the situation where Yellow is on the other side of Blue?

In this case both boats are on the same tack, overlapped, and not on the other boat's leeward side, so both boats are "windward" boats.

The question now is that if a boat meets the definition of [leeward, windward] does that automatically make the other boat a [windward, leeward] boat?  Just because you are windward or leeward doesn't make the other boat the opposite, you have to apply the definitions individually to each boat.  In these cases you don't have both a windward *and* leeward boat.  You have either two "leeward" boats or two "windward" boats but no leeward/windward combination.  RRS 11 only applies to windward and leeward boats.  In both cases, you cannot determine a ROW boat.  Both boats break RRS 14.  As neither boat is ROW or entitled to room, RRS 14(b) will not exonerate either boat.

It is indeed a classic scenario.

One week after it was pointed out to me, I had it happen on a very badly laid start line of a match race. The port entry thought he was being very clever sailing by the lee on starboard along the line. Unfortunately. she gybed, as he passed to windward of the starboard entry boat, and het boom hit the other boat, which made the decision easy. Since then, it has also happened a number of times at mark 4 on a standard team racing course where a boat executing a "gybe back" meets a boat that has rounded mark 4 and tacked onto starboard.

The only rule that applies is rule 14. They are overlapped and both are windward boats, by definition.

Yellow is actually on port tack.

Need to check definitions both for "Tack" and also "windward and leeward"

A boat sailing by the lee's windward side is that side opposite to the side her boom is on, and a boat is on the tack corresponding to her windward side, so Yellow is on port tack.

Makes it a straightforward port v starboard rule 10.

Yellow required to keep clear and failed to do so.

Seems straight forward. Am I missing something?

Both boats are on starboard.  When sailing by the lee a boat's leeward side is the side on which cher mainsail lies, the other side is her windward side.  The boat's main is on her port side, therefore, her windward side is her starboard side.  Her tack corresponds to her windward side so she is on starboard tack.

Doh!

Thanks

It's not an uncommon scenario for boats that have rounded a windward mark to meet with boats sailing to the mark.     Agree that it's great race management practice to set an offset mark to separate the traffic, but that's not always the case and there will be frequent meetings between boats on starboard beating to the mark and boats on starboard running to the leeward mark.

If yellow were not sailing by the lee, and were sailing either straight down the page or from right to left down the page then Yellow would be the windward boat and thus the keep clear boat under RRS 11.

If the boats collided, yellow would be impacted on her leeward side (as that's the side her boom is stationed).    Does that not make this a rule 11 situation?

I can imagine that Lasers and Finns encounter this situation frequently.   Any wisdom from those who officiate those classes?

I am not sure whether your question about RRS 11 is about the original situation or your situation where Yellow is not by the lee.

In the original situation, IMHO, RRS 11 does not apply as there is no windward boat as needed to apply the rule.  In your situation, Yellow would be windward and therefore keep clear.

Hi John,   I don't have deep expertise to offer here, I'm low on the totem pole and seek only to learn.

Blake, could you perhaps tell us the rules each boat said the other broke on their protest forms?

As a middle/back of the fleet Laser sailor I have been in this situation often in large fleets, 50 boats +.  In light weather, no waves to surf, if they hit each other they are duffers and if they go to the protest room, after reading the above comments I would expect them both to be disqualified.  However the most common situation when surfing is possible, is where the blue boat is on port tack and yellow is attempting to catch waves.  Blue must keep clear but yellow is not maintaining a steady course.  If I have ended up on the left of the course, something I avoid when down the back now. Crossing in front of the leaders on port tack when approaching the top mark is scary.  Then you need to find a space in the starboard tack queue to the mark.  On a couple of occasions the yellow boat has indicated that he wants me to hold my course, which I do and no mishaps so far.  Eventually some hard nut will enforce his ROW.  So who will win in the protest room?

Andrew - asking questions is the best way to learn.  I hope my response didn't offend you in any way.

David - who knows what will happen in a protest room.  In this case it may come down to whether the judges have thought about this problem or have been exposed to it before or if the parties understand it.  If I had to guess between the possible outcomes; penalize only Blue, penalize only Yellow, penalize both, or penalize neither, my guess is that the result would be to penalize Yellow.  I think the tendency is for people to think that the boat going upwind is ROW over the boat going downwind as upwind == windward and downwind == leeward.

John, no offense taken at all.  Not in the slightest and yes, I'm asking to learn.

David, I agree that considering these situations in advance is the best way to support and advise our fleet members.   I agree that the typical sailor, racer or otherwise, would expect the boat running to be considered the windward boat and the RRS to require it to keep clear, as the COLREGS do.

But RRS 11 is very specific.  "When on the same tack, overlapped", etc.

I contributed an artiles whose title is "Strange Case #02 - Both Leeward and Both Starboard"
on my poor sailing blog 20 years ago.

"Strange Case #02 - Both Leeward and Both Starboard" 
updated: Feb 14, 2010
Here is a question about the Racing Rules that has been bugging me since it happened to me in a regatta over a year ago.
Here is the situation...

Both_11_jpeg

FACTS:
Boat 1 (Blue) on starboard tack is sailing by the lee.
Boat 2 (Red) on starboard tack is sailing close-hauled.
Neither boat changes course.
The two boats make contact when the end of the boom of the Blue boat brushes the sail of Red.

APPLICABLE DEFINITIONS and RULES: 
-Rule 11: On the same tack, overlapped:
When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat.
-Tack, Starboard or Port: A boat is on the tack, starboard or port, corresponding to her windward side.
-Leeward and Windward: A boat’s leeward side is the side that is or, when she is head to wind, was away from the wind. However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies. The other side is her windward side. When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.

QUESTION:
OK. Here is why I am mystified by this one.
The Blue boat is sailing by the lee and so her leeward side is the side on which her mainsail lies, the port side. Therefore she is on starboard tack.
The Red boat's port side is her leeward side because it the side away from the wind.Therefore she is also on starboard tack.
Clearly the boats are overlapped so Rule 11 applies.
But which boat is windward and which is leeward?
Both boats could claim that they were the leeward boat because contact was made with the the leeward side of the other boat. On the other hand both boats would also have to concede that the other boat is on their own leeward side.
So have both boats infringed Rule 11? Or neither? Or if only one has, why?

ANSWER:
Mr. Dick Rose* opined as follows... (*ISAF RRC Section C Working Party)

The boats are overlapped, since neither is clear ahead or clear astern of the other. The next step would be to figure out which boat is leeward, or in the lee of the other. The definition of leeward when sailing by the lee is the side the boom is on. Because the boats are meeting, neither the upwind nor the downwind boat is in the other's lee. This situation makes all but rule 14 non-applicable. If a protest were to come up for contact between boats in this sketch, the odds would be for the committee to toss both boats for failure to obey rule 14.

Point of detail: 
I am sure that Mr. Rose is well aware that although Rule 14 does require boats to avoid contact if reasonably possible, neither boat can be penalized by the protest committee unless there is "damage or injury".

I think this is only true if a boat has ROW or an entitlement to room. Since neither boat has either of those in this scenario, neither is exonerated even though there was not damage or injury. . 

I contributed an articles whose title is "Strange Case #02 - Both Leeward and Both Starboard"
on my poor sailing blog 20 10 years ago.

"Strange Case #02 - Both Leeward and Both Starboard"
updated: Feb 14, 2010
Here is a question about the Racing Rules that has been bugging me since it happened to me in a regatta over a year ago.
Here is the situation...

Both_11_jpeg

FACTS:
Boat 1 (Blue) on starboard tack is sailing by the lee.
Boat 2 (Red) on starboard tack is sailing close-hauled.
Neither boat changes course.
The two boats make contact when the end of the boom of the Blue boat brushes the sail of Red.

APPLICABLE DEFINITIONS and RULES:
-Rule 11: On the same tack, overlapped:
When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat.
-Tack, Starboard or Port: A boat is on the tack, starboard or port, corresponding to her windward side.
-Leeward and Windward: A boat’s leeward side is the side that is or, when she is head to wind, was away from the wind. However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies. The other side is her windward side. When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.

QUESTION:
OK. Here is why I am mystified by this one.
The Blue boat is sailing by the lee and so her leeward side is the side on which her mainsail lies, the port side. Therefore she is on starboard tack.
The Red boat's port side is her leeward side because it the side away from the wind.Therefore she is also on starboard tack.
Clearly the boats are overlapped so Rule 11 applies.
But which boat is windward and which is leeward?
Both boats could claim that they were the leeward boat because contact was made with the the leeward side of the other boat. On the other hand both boats would also have to concede that the other boat is on their own leeward side.
So have both boats infringed Rule 11? Or neither? Or if only one has, why?

ANSWER:
Mr. Dick Rose* opined as follows... (*ISAF RRC Section C Working Party)

The boats are overlapped, since neither is clear ahead or clear astern of the other. The next step would be to figure out which boat is leeward, or in the lee of the other. The definition of leeward when sailing by the lee is the side the boom is on. Because the boats are meeting, neither the upwind nor the downwind boat is in the other's lee. This situation makes all but rule 14 non-applicable. If a protest were to come up for contact between boats in this sketch, the odds would be for the committee to toss both boats for failure to obey rule 14.

Point of detail:
I am sure that Mr. Rose is well aware that although Rule 14 does require boats to avoid contact if reasonably possible, neither boat can be penalized by the protest committee unless there is "damage or injury".

could it not be claimed that Blue (assuming that Blue is sailing on the next leg of the course) was very much clear ahead (by miles!) of Red?  

In olden times the COLREGS gave ROW to a boat beating to windward over a boat "sailing free."
Probably the racing rules did, too.
This would have solved our present problem.
The COLREGS and indeed the RRS were developed to give ROW to the boat least able to maneuver.
Starboard was less able to maneuver than port when her leeboards and rudder (always on the starboard side away from the port's wharf) were angled up out of the water. 
Likewise a boat "sailing free" could make a change of course without significant loss, while a boat "beating to windward" would sustain loss in VMG.
(Ditto: a boat coming downstream vs a boat working its way upstream.)

US Inland Steering and Sailing Rules still has this.

Rule 14 Head-on Situation: (d) Notwithstanding paragraph (a) of this rule [port-to-port passage], a power-driven vessel operating on the Great Lakes, Western Rivers, or waters specified by the Secretary [of Transportation], and proceeding downbound with a following current shall have right of way over an upbound vessel, shall propose the manner of passage, and shall initiate the maneuvering signals prescribed by Rule 34(a)(i), as appropriate.

Greg - I would argue that red is no more or less clear ahead of blue than blue is of red.  What if blue was going to a mark that red had already rounded?
Phil - Many of the rules were written to give the boat ahead the advantage, after all, why would you permit a boat to luff?  Shouldn't the boat ahead be required to sail her course while being overtaken so the trailing boat knows where they can't go?

I agree John, depending upon where on the race course this occurs, either boat could be leading.  My point is simply that (except before the start) one boat IS clear ahead of the other.  Is it too much to then posit that clear astern should keep clear? ;)

Greg -- This is the definition of clear ahead and clear astern from the RRS --

Clear Astern and Clear Ahead; Overlap 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. The other boat is clear ahead. They overlap when neither is clear astern. However, they also overlap when a boat between them overlaps both. 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. 

Notice that there's nothing in there about one boat leading another. Unfortunately, even if it seems logical, you can't add something to the RRS that doesn't exist in it. 

Today's Starboard Portal webinar at US Sailing studied sail vortices in kinetic sailing, including S-turns in sailing downwind.
This research clearly shows that the S-Turn technique creates the greatest drag forces (good) downwind.
If we see that the downwind Laser is maneuvering to maximize speed, he is a moving target that the upwind Laser cannot predict.

Phillip: You say this is "Kinetic sailing".  This diagram looks like "rocking", rule 42.2.2 violation. 

Is it, or is she rolling to facilitate steering, permitted by 42.3(a)? 

And if the downwind boat is (legally) altering course, does that change the situation? 

What are called S-Turns above is a common technique used by better Laser sailors downwind especially in waves where it also promotes surfing.  When sailing upwind on a possible collision course with the S-Turning downwind boat who has ROW, regardless of which tack they may be on?

Neither boat is ROW and neither needs to keep clear of the other by any rule.

Going rule by rule:
Section A
* RRS 10 doesn't apply, they are on the same tack.
* RRS 11 doesn't apply, they are both leeward boats WRT to one another.
* RRS 12 doesn't apply, neither is clear ahead or astern.
* RRS 13 doesn't apply, neither is tacking.
Section B
* RRS 14 always applies.
* RRS 15 doesn't apply, neither boat acquires the ROW.
* RRS 16 doesn't apply, neither is ROW.
* RRS 17 doesn't apply, neither became overlapped from clear astern.

As clear as mud.  Think I will avoid getting in this situation.

Yellow is not sailing a proper course and sail 
 another leg so rule 24.2 is infringed by yellow. Is all

I would be glad (and, in my opinion, justified) to make that ruling, Alvaro.
However, the Laser sailors would howl and I would never be invited to judge for them again.