In my view the answers are -
1. Yes. Green had to alter course to take avoiding action so blue failed to keep clear, see definition of keep clear
2. No. blue was approaching the mark and green was leaving it so no part of rule 18 applied, see 18.1(c)
3. N/a see answer to 2.

1. Yes - per your explnation, "Green must curtail her turn in order to avoid contact with Blue."  
2. N/A, rule 18 does not apply between Blue and Green
3.  N/A, rule 18 does not between Blue and Yellow

no blue probably broke no rule. Untill there was a colission course blue could continue freely. the other boat was subject to 16.1 so even wnen there was a collission course she had to give blue roon to keep clear, probable roon to continue.
I am for blue.

1.NO, at all positions 1,2,3  Green "can sail her course with no need to take avoiding action" so Blue is keep clear (see the Definition). See CASE 76 also...ups! - CASE 76 Withdrawn for Revision ))
2. NO, rule 18 does not apply between Blue and Green by rules 18.1(b) & (c).
3. N/A see answer # 2.

When I gave my original answer I did consider the 16.1 implications of green bearing away and whether or not this exonerated blue from any blame. The way the rules are written convinced me that if blue had tried to keep clear of green by bearing away but had been unable to do so then green's alteration of course would have been to meet her obligations under 16.1 and 14 and no rule would have been broken. The diagram shows clearly that blue did not do this and in fact made no alteration of course to try and keep clear but sailed on effectively making green change course to avoid her, That is the reason I think that 16.1 is not a factor here and blue broke rule 10.

I concur with Bill Handley's comments.  Green was free to bear away provided she complied with Rule 16..1.  Based upon the diagram, Blue had room to keep clear but failed to do so, apparently making contact with Green's boom and/or mainsail.  In addition to Rule 10, Blue also violated Rule 14.  Rule 18 does not apply.

I think Case  is pretty much on point here.  No rule was broken.  The only way that Green would collide with Blue is if she altered course to leeward, in which case she has to give Blue room to keep clear.  When Green held course ("curtailed her turn"), Blue kept clear, so Green didn't break and Blue didn't break .  Additionally, might apply.  At position 2, Blue is clearly sailing to pass astern of Green.  As Blue is passing astern of Green, Green cannot alter course in such a way so as to require Blue to immediately change course to continue keeping clear.  However, Green did not cause Blue to alter course and therefore did not break .  

Paul - I am not sure that you can apply rule 16.2 in this situation. When blue is in position 4 she is sailing astern of where green was in position 2 but when the boats conflict which is somewhere around position 3 it appears to me that blue is keeping clear (if in fact she is keeping clear) by passing ahead of green as demonstrated by the fact that if green had born away contact would have taken place between her bow and blue's port side.

Put simply if the potential contact was with greens bow then blue could not be sailing astern of her which is a precondition for 16.2 to apply

Bill,
This is the endless argument in team racing.  If what you are proposing is true, anytime a starboard boat hunts a port boat, 16.2 would not apply.  I don't beleive that is the proper interpretation of the rule.  Many disagree, but I believe 16.2 applies when port intends to pass astern of starboard, even if starboard later changes course such that port cannot pass astern (thus breaking 16.2).

No rule broken as green would have to change course into blue in a way that blue can't take further action.

I've often had a similair arguement with the starboard-leeward rounding where once rounded, a boat ahead tacks onto port .. and a boat behind just finishing her rounding rounds-up (on stb) to her beat course into the stern of the now port tacker who can't tack out of her way.

I'd say in both cases, the "change-course & stb boat" has to delay their turn if they are so close that the port-tacker is put into a position of not being able to keep-clear.

Ang

Oops!  I misread the diagram and wish to retract my comments after the first sentence above.  No foul.

Does changing course mean changing compass heading such as when the tiller/wheel already has the rudder turned from the keel line? IeDoes the fact that the boat is sailing an arc means she is constantly changing course?

Or does changing course mean changing the rudder or trimming the sails in such a way that the boat is now going to go in a different direction from that which she would have gone before the change?

I ask because if Green was sailing an arc that would bring her into collision with Blue and sailing that arc was not changing her course then Blue didn't keep clear and Green had no obligation to give room to keep clear as she didn't change course, so I would find for Green

If on the other hand we are talking about course as compass heading then Green is constantly changing course and so constantly having a new obligation to give Blue room to keep clear (which Green did so no breach of rules by either Blue or Green). It seems to me that at some stage 16.1 does in fact limit hunting if the hunting boat is constatnly changing course towards the give way boat, which is what I understand by the expression hunting. The hunter can still call on the boat to change course and protest if it doesn't but if the right of way boat has got itself too close and the change of course would inevitably cause a touch almost immediately if the keep clear boat changed course in either direction, then the Hunter has sailed themselves into a position where they have breached 16.1

So does Blue have to anticipate that given that Green is sailing an arc once she commences or increases her turning at the mark and therefore Blue has to keep clear of the arc in which Green is sailing? If yes then Blue didn't keep clear as port give way boat. If no I would find for Blue.

Paul H.

"Course" is not a defined term, therefore its definition is the common understanding of the word and I would contend the general understanding is "direction through the water". That said, a course change does not require any action on the rudder or sails.

For instance you are sailing on the wind in the groove with the wheel locked and sails cleated (boat is sailing itself) and you get a big lift and the boat turns-up .. You have changed course. If you were STB and a port boat was just crossing you and last min you get a lift and head-up (even though you don't adjust anything) .. you have changed course and must give Port opportunity to keep-clear.

Thanks Angelo, but if you have your rudder off the centreline as you are turning to round a mark are you changing course if you just follow the same arc?

Can your course be the arc, or is your course at any point in time the extension forward of the keel line?

I take your point about stbd lift/port knock situation or vice versa that creates the likelihood of a collision where there was none only moments before. That seems to imply that if the compass heading of the keel line changes then the course changes, no matter the cause of the change in couirse? (ie it could be a direction lift/knock, a velocity lift/knock, an adjustment of rudder, sails or weight, or even changing current speed.)

Paul, I can see your confusion as you can put a modifier in front of the word "course" to describe different types of courses ... i.e. "circular course, varying course, random course" .. etc. When "course" is used unmodified in the sailing parlance, then it means a straight course, regarless of where the sails are or where your tiller is turned. So with that said I can answer your questions directly.

but if you have your rudder off the centreline as you are turning to round a mark are you changing course if you just follow the same arc?

Yes. You are continuously making changes to your course. If you ever took calculus (and remember any of it), you are making an infinite number of infinitesimally small course changes as you carve a circular course.

Can your course be the arc, or is your course at any point in time the extension forward of the keel line?

The extension forward of that line at that moment. You are a rock in a sling being twirled overhead .. and at any moment the twirler lets the sling go and the rock flies straight away. That is your course at that moment.

I take your point about stbd lift/port knock situation or vice versa that creates the likelihood of a collision where there was none only moments before. That seems to imply that if the compass heading of the keel line changes then the course changes, no matter the cause of the change in couirse? (ie it could be a direction lift/knock, a velocity lift/knock, an adjustment of rudder, sails or weight, or even changing current speed.)

Yes. For instance, given my previous scenario of you on STB and a boat just clearing you on Port and you on STB get a lift, you do not necessarily have the right to sail that lift up into the port boat. Your course is your direction through the water, your course isn't your relative heading to the wind. So in the instance above, you'd actually have to fall-off into the lift to "hold your course", if by sailing up into the lift, the port passer would not have an opportunity to keep clear (i.e. .. he was clearing you, but you get a lift last min and now you are pointing at port's stern quarter).

Hope that helps.

Ang

I think Case 92 throws a little light on the question of changing course. In that case S bears away in a fairly consistent arc requiring P to take avoiding action. In the Decision this action by S is described as "changing course" so that suggests to me that the altertion of the heading is a change of course.

Thanks Bill & Angelo.

Rule 18, Mark-room does not apply since Blue is port and all other boats are on starboard. Questions 2 and 3 are not relevant since this is not a mark-room scenarios. Blue broke Rule 10. Green (ROW) had to alter course to avoid contact.

I see no evidence in the diagram that "Green (ROW) had to alter course to avoid contact." At no point in time is Green on a collision course with Blue, therefore Green was able to sail her course with no need for avoiding action, therefore Blue kept clear of Green.

A better way to describe the situation is that Green could not alter her course in the way that she wanted because, if she did, it would cause contact with Blue. The is consistent with Green meeting her obligations under Rule 16.1.

1) No.
2) No, per 18.1(c).
3) N/A.