New Posts New Posts RSS Feed: Laying the windward mark
  FAQ FAQ  Forum Search   Register Register  Login Login

Laying the windward mark
 Post Reply Post Reply Page  <1234>
Author
  Share Topic Share Topic  Topic Search Topic Search  Topic Options Topic Options
gordon View Drop Down
Really should get out more
Really should get out more


Joined: 07 Sep 04
Online Status: Offline
Posts: 1037 		Post Options Post Options   Quote gordon Quote  Post ReplyReply Direct Link To This Post Topic: Laying the windward mark
    Posted: 02 Jul 10 at 10:53am
Eitheryou're attached to the sea bed, in which case you are measuring the true wind, or you're not in which case you are measuring what I have heard described as the "sailor's wind".

Line should be square to sailor's wind, beat should be set downtide (looking up the beat) of the sailor's wind and run downtide (looking down the run) of sailor's wind. The ideal course in a cross current is thus a W walking the course downtide.

For most racing getting the run more or less right will give the best racing (especially in the "downhill skiing" classes). 

Gordon
Gordon
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: 6644 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 10 at 11:07am
Originally posted by gordon

For most racing getting the run more or less right will give the best racing


Yeah, I agree that the run is probably more critical than the beat these days, especially in mixed fleets...

Consider: if the run is square downwind gybing boats might easily be sailing 50% more distance than say a Laser. If the run is maybe 10 degrees out its (finger in the air guess) going to be perhaps a little as 10% more. OTOH to my mind in most circumstances 10 degrees out of the beat makes far less difference.
Back to Top
Guests View Drop Down
Guest Group
Guest Group
Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 10 at 11:44am

Thanks guys, Good stuff and I'm making notes.  

So how many clubs race courses have runs that are that accurate? ....and of course some course shapes seem to be dictated  by what boat the OOD sails.

Think I'll get some cotton "wands" made up and stick them in the ribs.

Edit...Gordon and Jim, what you say makes good sense.....but what lengths would you personaly  go to in a club race to achieve the "W" upwind and a square run down wind?

 



Edited by GK.LaserII
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: 02 Jul 10 at 12:32pm

At Hunts we try to encourage a course that has 2 good beats (at slightly different angles to try and take the shifty wind in to account. 2 good reaches (1 tight, 1 broad) and a run. That way we get fair racing for all classes.

Unfortuntely as with any amateur run club some ROs are better than others and we end up with a lot of fetches and reaches which favour certain classes of boat.

What is good though is that the sailors who are at the front of the fleet normally get together and have a chat and propose a better course to the RO during the lunch break. it is of course up to the RO if he decides to listen!
Paul
----------------------
D-Zero GBR 74
Back to Top
ColPrice2002 View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 25 Nov 08
Location: United Kingdom
Online Status: Offline
Posts: 221 		Post Options Post Options   Quote ColPrice2002 Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 10 at 12:36pm

Hi,

Given that on our inland water there always a slight variability in wind direction, I prefer the line to have a slight port bias - this gives a little more thought to the starting process.

Colin
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: 6644 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 10 at 1:07pm
Originally posted by jeffers

At Hunts we try to encourage a course that has 2 good beats (at slightly different angles to try and take the shifty wind in to account.


I've come to the (controversial) conclusion that if you do that (its traditional at my club too) the almost inevitable result is that you will get a fetch on every lap because if the wind swings one way one will be a fetch, if the other way the other one will be unless the angles are so close to each other they have no practical effect anyway.

I've been doing a lot of thinking about courses at my club, and although I'm sure noone agrees with me, the conclusion I've come to (for the moment: probably change my mind after I get to try it!) is that a good option for medium sized inland venues would be a lower case d shaped course: effectively a sausage on top of a triangle, with a gate/start at the top of the triangle. The triangle would have legs about 2/3rds length of the sausage, and you'd look to aggressively move the windward mark in a radius round the gate to cope with windshifts, but leave the triangle unaltered no matter what. Ideally one leg of the triangle would be a good spinnaker reach, one too shy for kites, and one a beat.
The sketch shows what I'd aim for in the centre, and the effect of 45 degree shifts on the triangle each side.



Of course you won't be able to fit that in at a lot of smaller (physically) clubs...

Edited by JimC
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: 6644 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 10 at 1:22pm
I think a lot of the criticism of club race officers is born of the fact that its a damn sight easier to set a decent course on the sea with steady winds.

Lets face it, if you can't set a half decent course in Portland Harbour at Weymouth when there's a reasonably steady breeze then you probably should consider manning the galley rather than the committee boat next time.

On the other hand if you're setting a course on the gravel pit at Much-Tickling-in-the-Marsh SC then you've got to consider:
the wind shadow from the trees up near marks 4 and 5 in an Easterly, but 3 and 4 in a N Easterly,
the persistent backing of the wind in the top rightcorner if its westerly, or veering if its gone round to the North,
the shifting wind coming round Top hill, which means that a beat on the left hand side of the lake is about 10 degrees backed compared the the right hand side if the wind is between 300 and 360 degrees, but the reverse between 250 and 300...
the shallow patch near the west end of the dinghy park where you mustn't set an upwind leg, but is OK to send people through on a run unless you've got the asymmettric class in the race...

and when you've struggled with all that and a 45 degree windshift 5 minutes after the start some little **** comes up after the race and tells you what a crap course you set, and how much better the race management is at Weymouth...


Edited by JimC
Back to Top
Guests View Drop Down
Guest Group
Guest Group
Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 10 at 1:55pm

Originally posted by JimC


and when you've struggled with all that and a 45 degree windshift 5 minutes after the start some little **** comes up after the race and tells you what a crap course you set, and how much better the race management is at Weymouth...

Too right, the first time I was OOD I didn't get it right and ended up getting criticised publicly on an open forum (Club Forum). Not a real prob for me because I can give better than I get. Some are more sensitive though...Definitely not constructive.

I am thinking of drafting (with the help of those more experienced) some electronic text for advice on our website though.



Edited by GK.LaserII
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: 02 Jul 10 at 6:29pm

Originally posted by JimC

I've come to the (controversial) conclusion that if you do that (its traditional at my club too) the almost inevitable result is that you will get a fetch on every lap because if the wind swings one way one will be a fetch, if the other way the other one will be unless the angles are so close to each other they have no practical effect anyway.

I've been doing a lot of thinking about courses at my club, and although I'm sure noone agrees with me, the conclusion I've come to (for the moment: probably change my mind after I get to try it!) is that a good option for medium sized inland venues would be a lower case d shaped course: effectively a sausage on top of a triangle, with a gate/start at the top of the triangle. The triangle would have legs about 2/3rds length of the sausage, and you'd look to aggressively move the windward mark in a radius round the gate to cope with windshifts, but leave the triangle unaltered no matter what. Ideally one leg of the triangle would be a good spinnaker reach, one too shy for kites, and one a beat.
The sketch shows what I'd aim for in the centre, and the effect of 45 degree shifts on the triangle each side.



Of course you won't be able to fit that in at a lot of smaller (physically) clubs...

I like your thinking Jim however at Hunts we can't fit those kinds of courses in unless the wind is from a prticular direction so we generally end up doing a tour of the lake throughout the race.

I have found that with a little care when setting the course (and watching to see if the wind is shifting in a consistent direction then having 2 beats at slightly different angles can work well, you can build the rest of your course round that (on our puddle).

Good input though, were our lake bigger I would be very tempted to try it. I have sailed in P and inverse P courses at a couple of nationals and they were enjoyable (I believe the Scorpion class have this written in to their nationals format so they don;t always get old olympic courses).
Paul
----------------------
D-Zero GBR 74
Back to Top
Guests View Drop Down
Guest Group
Guest Group
Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jul 10 at 12:41pm

As a footnote:

Asking around it seems that expectations of a quality club course vary quite considerably (as I would expect) but generally it seems that younger competetive sailors go to opens to satisfy their need for good racing and aren't too bothered about the club course. Some of the older sailors who don't do the opens (anymore) and who are just as competetive seem to be fussier obout the club course.......so I suppose it depends on whether you depend on opens or club racing for your yearly fix.

.......as a coincidence we had a "P" shaped course this week with the shorter leg being a run, conditions would have let me plane if I did the angles but I didn't fancy a hoist, gybe and drop on such a short leg. The previous leg was too tight for the spinny..........the cons of a symmy (or the cons of being a lazy bugger). Very enjoyable races though.

 



Edited by GK.LaserII
Back to Top
 Post Reply Post Reply Page  <1234>

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