New Posts New Posts RSS Feed: Tacking in zone
  FAQ FAQ  Forum Search   Register Register  Login Login

Tacking in zone
 Post Reply Post Reply Page  123 6>
Author
  Share Topic Share Topic  Topic Search Topic Search  Topic Options Topic Options
jeffers View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 29 Mar 04
Location: United Kingdom
Online Status: Offline
Posts: 3048 		Post Options Post Options   Quote jeffers Quote  Post ReplyReply Direct Link To This Post Topic: Tacking in zone
    Posted: 13 Apr 16 at 9:02am
Originally posted by Brass

Can B pass the mark without hitting Y?

How is that not 'preventing' B from passing the mark?

18.3 states:

(a) shall not cause the other boat to sail above close-hauled to avoid contact or prevent the other boat from passing the mark on the required side,

In your contrived example B is well above the layline and could come up to a close hauled course and still leave the mark on the required side. Once they are past the mark it becomes a windward leeward situation.

There is no mention of B being entitled to sail their proper course in 18.3 just that they be allowed to leave the mark on the required side. Which, in this case, had they come up to a close hauled course, they could have.

This is why being on the layline is key as it closes off these situations.


Edited by jeffers - 13 Apr 16 at 9:04am
Paul
----------------------
D-Zero GBR 74
Back to Top
Brass View Drop Down
Really should get out more
Really should get out more


Joined: 24 Mar 08
Location: Australia
Online Status: Offline
Posts: 1151 		Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 11:15pm
Originally posted by Jon Meadowcroft

This seems a pretty pointless and unrealistic example

In the starting position Y is downwind of B who is on the lay line. Apparently by pointing the boat head to wind after a tack Y gets its transom past the mark before B gets there.

It does not happen like this!

If it could happen Y tacked in the zone. I don't think she wants to be hanging about waiting for anyone else to turn up. B can easily sail over the top has physics has to make Y stop!

We are discussing the operation of a rule.  Of course the example is contrived.  I'm trying to examine what happens at the boundaries of the rule.

I disagree that it couldn't happen in practice.

If Y had passed head to wind before reaching the zone, it would be a routine mark-trap, so all that is needed is for Y to misjudge her position with respect to the zone boundary when she tacks.

B has never been on the layline.  B is always well above the layline.

If B is on the layline, she's nearly always going to get the benefit of rule 18.3( a ) first sentence.
Back to Top
Brass View Drop Down
Really should get out more
Really should get out more


Joined: 24 Mar 08
Location: Australia
Online Status: Offline
Posts: 1151 		Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 11:06pm
Originally posted by JimC

Not sure what you mean... 

Can B pass the mark without hitting Y?

Isn't that Y preventing B from passing the mark?

Originally posted by JimC

 if she goes in front of yellow and past close hauled then that's the first sentence of 18.3(a). 

Yes, if it is possible for B to luff up past her close hauled course before she hits Y

 
Originally posted by JimC

I don't think we need the "prevent" clause in this situation since if Blue goes behind yellow she's entitled to mark room (18.3b), and 

Disagree.

If B bears away, she will be clear astern of Y.
Back to Top
Jon Meadowcroft View Drop Down
Groupie
Groupie


Joined: 26 Aug 08
Location: United Kingdom
Online Status: Offline
Posts: 64 		Post Options Post Options   Quote Jon Meadowcroft Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 9:05pm
This seems a pretty pointless and unrealistic example

In the starting position Y is downwind of B who is on the lay line. Apparently by pointing the boat head to wind after a tack Y gets its transom past the mark before B gets there.

It does not happen like this!

If it could happen Y tacked in the zone. I don't think she wants to be hanging about waiting for anyone else to turn up. B can easily sail over the top has physics has to make Y stop!
Back to Top
Rupert View Drop Down
Really should get out more
Really should get out more


Joined: 11 Aug 04
Location: Whitefriars sc
Online Status: Offline
Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 6:38pm
I assume blue doesn't have to predict at point 4 that yellow will stay htw past the mark, and by stage 5 will need to go past close-hauled, so blue is wrong.
Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
Back to Top
JimC View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 17 May 04
Location: United Kingdom
Online Status: Offline
Posts: 6661 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 5:03pm
Not sure what you mean...
I don't think we need the "prevent" clause in this situation since if Blue goes behind yellow she's entitled to mark room (18.3b), and if she goes in front of yellow and past close hauled then that's the first sentence of 18.3(a).
Back to Top
Brass View Drop Down
Really should get out more
Really should get out more


Joined: 24 Mar 08
Location: Australia
Online Status: Offline
Posts: 1151 		Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 3:31pm
Can B pass the mark without hitting Y?

How is that not 'preventing' B from passing the mark?
Back to Top
jeffers View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 29 Mar 04
Location: United Kingdom
Online Status: Offline
Posts: 3048 		Post Options Post Options   Quote jeffers Quote  Post ReplyReply Direct Link To This Post Posted: 12 Apr 16 at 12:11pm
Originally posted by Brass

Originally posted by JimC

Gosh Brass, you're interpreting 'prevent' very differently from me. I was thinking that it meant forcing the other boat the wrong side of the mark.

That's certainly the example the commentaries discuss with respect to 'prevent'.
 

OK.  What does anyone think about Diagram 2, where Y deliberately puts on a mark-trap?


I would guess it is Rule 11 as Y is not preventing B from passing the mark on the correct side (so doesn't break 18.3) as B is well above the layline they could head up..
Paul
----------------------
D-Zero GBR 74
Back to Top
Brass View Drop Down
Really should get out more
Really should get out more


Joined: 24 Mar 08
Location: Australia
Online Status: Offline
Posts: 1151 		Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 16 at 8:49pm
Originally posted by sundowner6959

If Y had not tacked below B but had been abreast and on the same starboard tack and on the layline within 2 boat lengths and the wind shifted 15 deg.(header) would Y not be entitled to shoot the mark with B giving room? 
Provided boats had been overlapped, not clear ahead/astern when the first of them reached three boatlengths from the mark

Absobleedinglutely.
Back to Top
Brass View Drop Down
Really should get out more
Really should get out more


Joined: 24 Mar 08
Location: Australia
Online Status: Offline
Posts: 1151 		Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 16 at 8:28pm
Originally posted by JimC

Gosh Brass, you're interpreting 'prevent' very differently from me. I was thinking that it meant forcing the other boat the wrong side of the mark.

That's certainly the example the commentaries discuss with respect to 'prevent'.
 

OK.  What does anyone think about Diagram 2, where Y deliberately puts on a mark-trap?



Edited by Brass - 11 Apr 16 at 8:28pm
Back to Top
 Post Reply Post Reply Page  123 6>

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz
Change your personal settings, or read our privacy policy