Note: This forum is not affiliated with World Sailing and comments on this forum do not represent an official interpretation of the rules, definitions, cases or regulations. The only official interpretations are those of World Sailing.
Teams Racing Call F2 - The "disappearing" obstruction
Ross Adams
Nationality: Australia
1
Hi all, Below you can see a screenshot from the Teams Racing Call Book. I am (sort of) OK with the "No Penalty" part of the answer but struggle to feel comfortable with the logic, that at position 2 A ceases to be an obstruction and rule 19 switches off. Further below I have a slight variation in the movement of the boats. In what I have drawn the gap between A and B is closed by the actions of B, rather than A.
So, pretty much the same as above,
Blue bares away to give green room between itself and yellow but as soon as Blue gets overlap with yellow it heads up and slams the door on Green. Here we will assume that Green has time and opportunity to head above yellow. So the situation goes from "Sure, I have to give you room between the obstruction and me" to "slam - unlucky, now I don't". Or at least, if I apply the logic in the above Teams Call Answer that is how it looks. Is my interpretation correct?
Lastly, for those with contacts with the good people that produce the call book there is a typo in Question 4 of this case.
" Similar to question 3, except that Y’s bow is about half of a boat-length ahead of B’s bow and B is steering a course directly toward A’s transom. At position 2, Y becomes overlapped to windward of A. Shortly thereafter, B bears away and passes to leeward of A. X protests. What should the call be? "
There is no boat X!!!!
Created: 24-Mar-13 12:40
Comments
Gordon Davies
Nationality: Ireland
Certifications:
International Judge
2
Blue bares away to give green room between itself and yellow but as soon as Blue gets overlap with yellow it heads up and slams the door on Green. Here we will assume that Green has time and opportunity to head above yellow. So the situation goes from "Sure, I have to give you room between the obstruction and me" to "slam - unlucky, now I don't". Or at least, if I apply the logic in the above Teams Call Answer that is how it looks. Is my interpretation correct?
At 1 Yellow is clear ahead of Green and Blue. Blue chooses to pass to leeward of Yellow and gives Green room as required by RRS 19.2(b). When Blue becomes overlapped to leeward of Yellow she acquires right of way. Yellow is no longer an obstruction for Blue. Blue must initially give Yellow room to keep clear, RRS15 Green is still clear astern of Yellow. Yellow is still an obstruction for Green. At the same time Green must continue to keep clear of Blue. When Blue changes course she must give both Green and Yellow room to keep clear, RRS 16.1. For Green, room includes room to keep clear of Yellow.
Created: 24-Mar-13 13:25
P
Michael Butterfield
Nationality: United Kingdom
Certifications:
International Judge
International Umpire
International Race Officer
1
seem correct I agree with Gordon's Comments.
Created: 24-Mar-13 13:32
Gordon Davies
Nationality: Ireland
Certifications:
International Judge
2
Thanks Mike. I hope that we continue to be in agreement - because I understand we will be seeing a lot of each other this summer!
Created: 24-Mar-13 13:34
P
Angelo Guarino
Certifications:
Regional Judge
Fleet Measurer
0
US36 offers a similar (counter) example and explanation of the rules … except in this instance the leeward boat did not provide room prior to 19.2(b) turning off.
When M became overlapped to leeward of W, the applicable rules changed. Even though L’s bow was well behind W’s stern, the overlap between L and W began at that time because M was between and overlapped with both of them (see the definition Clear Astern and Clear Ahead; Overlap). Rule 12 no longer applied, and rule 11required W to keep clear of M and L. W was no longer a right-of-way boat or an obstruction to L and W; therefore, L was no longer required by rule 19.2(b) to give M room between herself and W. Rule 15 required L and M to initially give W room to keep clear, and since both M and W were required to keep clear of L, L became an obstruction to M and W.
Just before M and L became overlapped with W, L failed to give M room between her and W as required by rule 19.2(b), as shown by the rules breaches and contact that occurred shortly after the overlap was established. As a result of L’s breach of rule 19.2(b), there was not space for M to give W room to keep clear after she became overlapped with W, as she was required to do by rule 15.
Created: 24-Mar-13 15:08
Ross Adams
Nationality: Australia
0
Hi All, Thanks for your comments.
I suppose one of the things i don't get is that in both diagrams I posted at the top 'A' (TR Call) and Yellow (my diagram) was never an obstruction to the leeward boat ("B" and Blue respectively). That is, the leeward boat in both examples can sail directly ahead and not hit the clear ahead boat.
I note the definition of Obstruction; "An object that a boat could not pass without changing course substantially"
No course change is required by the leeward boat, so there is no obstruction as far as they are concerned.
So when the TR Call says "...A is no longer an obstruction (to the leeward boat B)..... rule 19 no longer applies to B and Y..."
But it was never an obstruction to B, as they were always going below it.
So if the leeward boat was required to move lower because of the clear ahead boat being an Obstruction to the windward boat. Then this does not change because the Leeward boat subsequently gets an overlap with the boat in front. The front boat is still an obstruction to the windward boat.
Thoughts?
Created: 24-Mar-13 23:07
P
Angelo Guarino
Certifications:
Regional Judge
Fleet Measurer
1
Ross, Read the TR Call and US 36 closely and the highlighted part of def: Obstruction below.
Obstruction: An object that a boat could not pass without changing course substantially, if she were sailing directly towards it and one of her hull lengths from it. An object that can be safely passed on only one side and an object, area or line so designated by the sailing instructions are also obstructions. However, a boat racing is not an obstruction to other boats unless they are required to keep clear of her or, if rule 22 applies, avoid her. A vessel underway, including a boat racing, is never a continuing obstruction.
It is stated in the negative above. Invert it and a boat that another boat must keep clear of is an obstruction to that boat. If 2 boats must KC of the same boat, that boat is an obstruction to both boats.
Created: 24-Mar-14 01:22
P
Angelo Guarino
Certifications:
Regional Judge
Fleet Measurer
0
Ross .. rereading your last question I think there may another concept about “obstruction” that you might be missing. That is that an obstruction doesn’t actually have to be in the path of a boat for it to qualify as an obstruction. I know that might sound a bit weird at first, but an object or a boat qualifies as an obstruction with no boat close to it.
You can see this in the 1st sentence of def: obstruction.
Obstruction: An object that a boat could not pass without changing course substantially, if she were sailing directly towards it and one of her hull lengths from it.
Look at the language in that sentence … it uses “could” and “if”. The definition asks you to imagine a boat sailing directly at the object in question from a distance 1 BL away. If that object passes the test, it IS an obstruction, even if no actual boat is approaching it.
The same thing is true for a boat that is an obstruction to another boat. If you are 1/2 mile clear-astern of another boat on the same tack, then that boat clear-ahead is an obstruction to you because you must keep clear of her under rule 12.
Rule 19 only applies when boats are “at” an obstruction. There is a difference between classifying objects and boats as obstructions and applying rule 19 when 2 boats are “at an obstruction”.
Created: 24-Mar-14 01:57
Ross Adams
Nationality: Australia
0
Thanks Angelo, "an obstruction doesn’t actually have to be in the path of a boat for it to qualify as an obstruction" that was definitely something I did not appreciate. Cheers, Ross.
Here we will assume that Green has time and opportunity to head above yellow.
So the situation goes from "Sure, I have to give you room between the obstruction and me" to "slam - unlucky, now I don't".
Or at least, if I apply the logic in the above Teams Call Answer that is how it looks.
Is my interpretation correct?
At 1 Yellow is clear ahead of Green and Blue. Blue chooses to pass to leeward of Yellow and gives Green room as required by RRS 19.2(b).
When Blue becomes overlapped to leeward of Yellow she acquires right of way. Yellow is no longer an obstruction for Blue. Blue must initially give Yellow room to keep clear, RRS15
Green is still clear astern of Yellow. Yellow is still an obstruction for Green. At the same time Green must continue to keep clear of Blue.
When Blue changes course she must give both Green and Yellow room to keep clear, RRS 16.1. For Green, room includes room to keep clear of Yellow.
I suppose one of the things i don't get is that in both diagrams I posted at the top 'A' (TR Call) and Yellow (my diagram) was never an obstruction to the leeward boat ("B" and Blue respectively). That is, the leeward boat in both examples can sail directly ahead and not hit the clear ahead boat.
I note the definition of Obstruction;
"An object that a boat could not pass without changing course substantially"
No course change is required by the leeward boat, so there is no obstruction as far as they are concerned.
So when the TR Call says "...A is no longer an obstruction (to the leeward boat B)..... rule 19 no longer applies to B and Y..."
But it was never an obstruction to B, as they were always going below it.
So if the leeward boat was required to move lower because of the clear ahead boat being an Obstruction to the windward boat. Then this does not change because the Leeward boat subsequently gets an overlap with the boat in front. The front boat is still an obstruction to the windward boat.
Thoughts?
It is stated in the negative above. Invert it and a boat that another boat must keep clear of is an obstruction to that boat. If 2 boats must KC of the same boat, that boat is an obstruction to both boats.
You can see this in the 1st sentence of def: obstruction.
Look at the language in that sentence … it uses “could” and “if”. The definition asks you to imagine a boat sailing directly at the object in question from a distance 1 BL away. If that object passes the test, it IS an obstruction, even if no actual boat is approaching it.
The same thing is true for a boat that is an obstruction to another boat. If you are 1/2 mile clear-astern of another boat on the same tack, then that boat clear-ahead is an obstruction to you because you must keep clear of her under rule 12.
Rule 19 only applies when boats are “at” an obstruction. There is a difference between classifying objects and boats as obstructions and applying rule 19 when 2 boats are “at an obstruction”.
"an obstruction doesn’t actually have to be in the path of a boat for it to qualify as an obstruction"
that was definitely something I did not appreciate.
Cheers,
Ross.