Zezo forum: Frozen Race

Frozen Race

Post by Nikki | 2013-04-05 | 11:12:02

Hi Will there be charts for the Frozen Race. Thanks for all your work you put into the charts. I only use Zezo so you are a great help to me.
Nikki

24 Comments

Post by kigwen56250 | 2013-04-06 | 11:26:05

Hello,
we can count on your support for The Frozen Race, because I 'used solely your fabulous tool, which I think is a simplicity and Efficiency formidable.
I thank you in advance.

Bonjour,
pourrons nous compter sur votre aide pour The Frozen Race, car j' utilises uniquement votre fabuleux outil , qui je trouves est d'une simplicité et d'une éfficacité redoutable.
Je vous en remercie d'avance.

Post by zezo | 2013-04-07 | 11:33:26

Race support is available at http://sail.zezo.org/fr/

I had not updated the site to affect the daylight savings time one week ago, so the winds may be somehow wrong at the moment. Should get in sync tonight.

Also keep in mind that the router may suggest stupid things in narrow channels and when the destination point is around a land mass (like Akpatok island). Please use intermediate waypoints to avoid the routing glitches.

Post by ozezo | 2013-04-07 | 11:37:28

Thank you very much :)

Post by papy_lanic | 2013-04-07 | 12:47:13

thank you well!! :)

Post by Ysland-TPN | 2013-04-07 | 18:40:00

Thanks a lot Cvetan for the Frozen Race. I just sent you a little donation to help your efforts. ;)
JP

Post by ujuj49 | 2013-04-07 | 23:14:08

Hello,
It seems to me that the boat's speed on zezo is wrong. It's not at all the speed displayed by virtual regatta.
Thanks a lot

Post by zezo | 2013-04-08 | 00:09:25

The wind forecast did not update for some reason. I was visiting my parents for dinner and was not home to watch it. Should be OK now, will be checking it tomorrow in the morning.

Post by the_gweg | 2013-04-10 | 00:49:27

Hi Cvetan, i m here for the first time, and i want to tell something: TKS, TKS, TKS a lot lot lot. Very beauthiful tool easy to access.
Is it possible to synchronize zezo with run GFS, i believe there s 1 hour difference .

PS: Sorry for my really bad english

Post by the_gweg | 2013-04-10 | 00:51:03

Hi Cvetan, i m here for the first time, and i want to tell something: TKS, TKS, TKS a lot lot lot. Very beauthiful tool easy to access.
Is it possible to synchronize zezo with run GFS (00Z, 00Z+, 06Z ..., i believe there s 1 hour difference .

PS: Sorry for my really bad english

Post by ultimateboat | 2013-04-20 | 14:08:52

Hi Cvetan,

It seems that above 80°N there is no wind, at least it isn't possible to see the proposed routing.
When you have time, you will be able to look at what is a problem, please?

Thanks Cvetan
Bye

Post by din0 | 2013-12-17 | 09:17:59

Frozen is back! 2nd leg starts friday evening.

Post by zezo | 2013-12-17 | 09:54:23

I'll check it. The problem with that race was that the chart ends at 80N and you can't sail past that.

Edit: Boat is MOD70, same as JV Multi.

Post by din0 | 2013-12-17 | 10:13:55

Same boat, but winds are in sectors. Jv_multi was interpolated.
80 N should be enough to the 1st course mark.

Paco has this link:
http://sail.zezo.org/fr/chart.pl

Post by zezo | 2013-12-17 | 10:19:06

Thanks. Have not noticed that at a first glance. Still drinking my coffee. The race will appear at that link later today or possibly tomorrow.

Post by din0 | 2013-12-21 | 00:41:03

There is something wrong with the router.
Check it out:
http://i44.tinypic.com/2ilklk7.jpg

Heading 255 at wind 7 is not TWA 110.

Post by zezo | 2013-12-21 | 09:19:14

Hmm. That's actually a feature ... for the races with interpolated winds where it's often better to sail at fixed twa. To avoid having black dot every 10 minutes I've relaxed the calculation of the angle.

With wind grids it's a bit different. The router tries tracks in 5-degree increments, so when it has to sail at 112, it actually sails at 110 for 10 minutes, then at 115 for 10 or 20 minutes and so on.

In the previous version you would see the averaged heading and that would be 112. In the current one you see the actual numbers.

I have to think a bit how to fix but still have the concept of fixed TWA in the interpolated winds. You can always use the track tool to see the actual direction and progress.

Besides, at those latitudes the great circle and the rhumb line diverge quickly enough to add 1-2 degree correction in a single wind cell.

Post by Phil | 2013-12-21 | 18:16:51

Hi !
So, what is better to follow... TWA or heading ?!?

Thanks a lot for your work ;)

Post by zezo | 2013-12-21 | 20:07:56

With wind cells it's more likely that the heading is what you really want. Use the track tool to double-check - red line/text is heading, green is twa and they do agree ;-)

Post by din0 | 2013-12-21 | 13:50:58

Ok, thanks. The idea of fixed TWA is very good. Especially for the interpolated races. I think there will only be interpolated races in future on VR, after Frozen and Clipper ends...

Post by Phil | 2013-12-21 | 18:17:35

Another question : what is "avoid tacks" ???

Post by ozze | 2013-12-23 | 11:47:31

limiter changement d'amure

Post by ghelle | 2013-12-22 | 11:03:54

Hello,

there is a difference between Virtualregatta data and Zezo.

By example at the same instant i have in VR :
TWA: 128 heading: 291 Boat speed: 17.4 Spi
and in Zezo :
TWA: 125 heading: 291 Boat speed: 18.51 Spi

Pacotool is ok like VR
The problem seems with wind maps?

Guillaume
boat : ghelle (PYR)

Post by zezo | 2013-12-22 | 11:15:58

See why wind angle, heading and TWA don't add in my message 5 posts above.

In your case the speeds corresponds to TWA 125. The router would actually sail at 125 for a while and then at 130 for a while. You could do the same or just head to 291.