Post by iconPost by zezo | 2016-12-09 | 16:53:36


I've made some additional changes to the router:

1. The wind interpolation algorithm should be closer match to the one used by VR. It's updated both in the router and the web interface (track tool)

The representation/rounding of the wind data should also match the new VR format (1 signed byte per U/V value)

2. The boat speed for the Vendee is multiplied by 1.06. I got few user reports that this is the case in the game engine.

The game interface itself does not apply that correction (which has lead me into the red line at least twice) so the displayed boat speed will differ by 6%

The first change is relatively big, so please drop me a note if you experience any problems/wrong data etc.

commenticon 76 Comments
Post by iconPost by Whaou | 2016-12-09 | 17:48:29
I just compare a track zezo with a track VR, in my case I am too short of twenty miles in 24 hours.
Maybe 1.06 is too strong in this case .
On VR the wind varies every hour.
If the wind accelerates 1.06 is too low. If the wind weakened 1.06 is too strong.
Difficult to find the right value.
Post by iconPost by zezo | 2016-12-09 | 17:50:58
The VR does NOT apply the correction, but it seems that the game engine/server does.

Please write down your supposed position after 2/3/6/whatever hours, according to the router and according to the game, and when the time comes compare the actual position to the prediction.
Post by iconPost by zezo | 2016-12-09 | 18:06:41
Doing the test myself now:

Supposed position in 2 hours (19h CET):

VR: 143E 30 25 50S 59 24 35.2NM
zezo: 143E 33 40 50S 58 25 37.6NM
Post by iconPost by KKAOSS | 2016-12-09 | 20:02:57

how are you, my friend?

i am off on my numbers in Vendee as well.
098 E 51 02 45 S 01 12 VR TWA 135 degrees WS 29.0 kts Boat Speed 21.8 HDG 85 degrees
same coords zezo VG TWA 135 degrees WS 29.1 kts Boat Speed 23.14 HDG 85 degrees

this is a rather large difference in Boat Speed wouldn't you say so?

Post by iconPost by zezo | 2016-12-09 | 20:25:00
That was the 6% intended difference.
Post by iconPost by pcayrol | 2016-12-09 | 20:08:18

Maybe it's also the random effects of the "RAFALE", isnt'it ?
Post by iconPost by marcusbelgicus | 2016-12-09 | 20:44:38
Yes this is what I think as well. I have looked at the boat speed that you have on the screen and the boat speed seen by the others and very often in the morning there is a significant difference (sometimes at least 10 %) and there is no reason to have such difference if you are in a stable windy zone.
Post by iconPost by zezo | 2016-12-09 | 20:26:06
I removed the speed increase now. Looks like it needs further investigation, and maybe should be made optional.
Post by iconPost by guigui | 2016-12-10 | 09:39:12
This night, in a 5 h segment, I made about 10 more miles than the 100 miles planned on zezo (No pro sail for me)
I think the boost should still be applied. Has it been removed on zezo yet ?, or the value changed. Can you please indicate somewhere what coefficient has been used for a given chart, near the view zoom value for example.
Make it optional is a good idea. But that will confuse people, even more than what we see in this discussion.
Post by iconPost by KKAOSS | 2016-12-09 | 20:48:28
you are doing such a fine job - keep up the excellent work!

Post by iconPost by Pousstoidlakeuj | 2016-12-09 | 21:14:18

I think VR stopped today the acceleration at 106,5% (it was constant all the week) : perhaps they think we are now near the leaders of the real Vendée, but I'll verify times to times...

For the winds and speed in Zezo, we are just perfect now : I am just testing the distance for an hour or two.

Many thanks for this job !
Post by iconPost by NORTHKOREAN | 2016-12-09 | 21:48:37
YES agree with pousstoidlakeuj, I tink VR topped the acceleration at 106,5% because the projection doesn't match beetwen zezo and VR
Post by iconPost by HugoHsl | 2016-12-09 | 23:04:07

is it normal that my boat has crossed the red line in the game when Zezo tell me that it shoudn't ? I crossed the red line several times, this is really anoying
Post by iconPost by pcayrol | 2016-12-09 | 23:21:38

I suggest you to take a margin... ;)

Post by iconPost by HugoHsl | 2016-12-09 | 23:23:12
That is to say ?
Will the problem be solved?
Post by iconPost by KKAOSS | 2016-12-09 | 23:44:42
@hugohsi - i agree with pcayrol - dude take a safe margin seriously i mean why put yourself in harms way - it really kills your speed - like from 22 kts down to 6.5 - PLAY SMART! zezo has programmed a fabulous routing software - it's time for you to use some of your software - uh like use your brain a little....zezo is an aide, the VR is THE GAME, so play THE GAME -it makes the rules not zezo!

Post by iconPost by HugoHsl | 2016-12-09 | 23:50:08
I agree with him too. That was not my question. I've discovered this routing software 2 days ago, i used my brain during all the race, i just want to know if this problem will be solved.
Post by iconPost by KKAOSS | 2016-12-10 | 00:02:59
sorry, my tone was not very nice -

I have used his program since he started doing it and he does his darn best. This, in my opinion, is a minor issue but I am sure he will address it eventually - he has a very good eye for detail and he is a patient guy. zvetan needs time to tinker. Meanwhile, make the buffer so you don't get speed violation, good luck!

~~~~~~~ _/) ~~~~~~ _/) ~~~~
Post by iconPost by zezo | 2016-12-11 | 22:24:37
Sorry, folks. I've removed part of your chat logs.

Have to keep the things more or less on topic.
Post by iconPost by zezo | 2016-12-10 | 10:34:28
I've crossed the red line 3 or 4 times myself. Not because what the router said but because of what the VR interface was showing.

The last time the boat was even visually above the red line, but i got a warning dialog. That was at a point where the line was running SE-NE, so I assume that the game engine uses different criteria to check vor violations.

The interface looks like Mercator projection now, so the straight lines there are rhumb lines. At that latitude great circle route should be below the rhumb line, so no problem if the check uses spherical geometry. Bit it's more likely to use linear interpolation and then the real limit will be above the red line.
Post by iconPost by marcusbelgicus | 2016-12-10 | 10:50:57
I got exactly the same issue than you zezo, boat clearly out of ZEA but still giving the message that my boat was in that zone.
Post by iconPost by Isatis | 2016-12-10 | 16:22:07
May be , VR changes the coeff for polars as they want, just to adjust the fleet with real boats. I read a comment on VR forum from on that. He seemed to be sure of that. May be a good thing that you put in the form , near the Gobutton a new case where every body could adjust the coefficient of polar as they like. I don't know if this is possible or not. Thank you for this good software and sorry for my poor English.
Post by iconPost by Pousstoidlakeuj | 2016-12-10 | 17:43:47
It seems to be very strange : the whole week it was at 106,5 % for me, and now I'm at 100 %. Somebody in forum VR continue with 106 % !!
Post by iconPost by zezo | 2016-12-10 | 19:33:21
Today the game shows 1-2 % higher speed for me than the polars.

Looks like VR are still making changes.

But it does not really matter that much. We are used to seeing the exactly same numbers in both interfaces but in the end 6 hours later the forecast changes and those 2% difference in boat speed are lost in the noise.

Edit: There are discrepancies even withing the game interface itself:

Wind: 23.3 according to the game, 23.27 according to my chart. TWA 150.
The game says 19.1 knots boat speed
Chart says 18.95
The game polar chart says 19.0 knots at 23.3 and 23.4
Post by iconPost by mak08 | 2016-12-11 | 00:36:08
Post by iconPost by zezo | 2016-12-11 | 10:03:15
mak08 had a comment here that the isochrones look a bit weird at 180 degrees East.

I checked and find an error (copy-paste typo) that misplaced the wind U and V components at 180 degrees that resulted in wrong wind speeds and directions. It was introduced during the last update of the wind interpolation few days ago.

Should be OK now.

Thanks for the notification.
Post by iconPost by Seche | 2016-12-11 | 09:11:51
Hi Zvetan
First visit to your fabulous tool.
Reading this morning your post: | 2016-12-09 | 16:53:36
I decided to not notice all iterations this morning from 06h25 to 08h05
Best regards. Seche

06H15 This morning. Position checked. Boat running 150° starboard to cape 117°.
Zezo calculate tack point at 07H55, and next at 08H55.
I use 1st scheduled tack at 07H55.

Datas of VR interface at each iteration from 06H25 to 08H05:

Time stamp - Position - angle - wind speed - boat speed - cape - ice limit target time (bottom of the tack point tangent to the limit)
!: this means:tack time moved

06H25 153 17 13 _ 52 10 58 150° STB 22.7 18.4 117° 07H55
06H35 153 22 09 _ 52 12 31 150° STB 22.7 18.4 117° 07H55
06H45 153 27 04 _ 52 14 02 150° STB 22.7 18.4 116° 07H55
06H55 153 32 01 _ 52 15 33 150° STB 22.7 18.5 116° 07H54!
07H05 153 36 58 _ 52 17 04 150° STB 22.7 18.4 117° 07H53!
07H15 153 41 52 _ 52 18 34 150° STB 22.6 18.4 117° 07H52!
07H25 153 46 44 _ 52 20 04 150° STB 22.5 18.3 117° 07H51!
07H35 153 51 34 _ 52 21 35 150° STB 22.5 18.2 117° 07H50
07H45 153 56 21 _ 52 23 05 150° STB 22.4 18.2 118° 07H50
07H55 154 00 32 _ 53 23 08 150° Port 22.3 18.1 058° 08H55
08H05 154 95 02 _ 52 21 22 150° Port 22.2 18.0 058° 08H55
Post by iconPost by zezo | 2016-12-11 | 10:20:46
The tack point can move when sailing at fixed TWA because the wind direction can change in the new forecasts, and we don't know exactly how the game does the weather updates now.

And then the directions we see in the user interface are rounded. Behind the scenes one of the numbers is fractional - either the TWA or the heading.

What's going on is (probably) that the TWA is really 150, but the real heading depends on wind direction, which is not rounded. then if you are sailing at 117.49 the game shows 117 as current heading and does the track projection with that number as a base. 10 minutes later you are sailing at 117.51, the game shows 118. Nothing has really changed but the projected track just moved 1 nm to the right at the 6 hour mark.

Just observing the tacking point is somehow meaningless in this context. It would be good with fixed heading, but not with the autohelm.

On the other hands the numbers you recorded can be quite useful if we calculate the distance and real boat speed based on it. I'll try to find some time for that today.
Post by iconPost by Michel | 2016-12-11 | 09:27:16

Il faut savoir que vous serez ralenti dès qu'une partie du bateau passera la ligne et pas le centre du bateau !!!
Sur mon PC à zoom maximal il y a 1,7 miles du centre du bateau au bout de la proue. En largeur il y a 0,8 mile par côté !
Des imoca plus grand qu'une piste pour Airbus 380 !

Donc gardez 2 miles de marge sur VR !
Bon dimanche à tous .
Post by iconPost by carlotta | 2016-12-11 | 10:31:54
Mise à jour fichier GFS à 5h our run de 00h00 pas faite : toujours les vents du run de 18h hier???
Post by iconPost by zezo | 2016-12-11 | 10:42:20
The 0Z GFS was probably delayed by NOAA. Happens sometimes.
My scheduled update failed with 'file not found' at both 5:00 and 5:50 (CET)

I updated manually around 7h
Post by iconPost by carlotta | 2016-12-11 | 10:45:08
But you tell 7h ...? what means 7h GMT...?
Post by iconPost by carlotta | 2016-12-11 | 10:49:29
Zygrib we have the 00h00 run...
Post by iconPost by carlotta | 2016-12-11 | 11:00:45
i hope at 11am we will ave the 6am run GFS, because at 10am we have alwyas the 18pm run
tnanks for your work
Post by iconPost by zezo | 2016-12-11 | 11:35:57

Sun Dec 11 05:12:49 2016 GMT

NOUS42 KWNO 110512

0508Z SUN DEC 11 2016


Post by iconPost by denisbarbier | 2016-12-11 | 12:51:40
Post by iconPost by carlotta | 2016-12-11 | 20:06:49
Always problem with update models?
at 7pm...always winds of 6am run...?
Post by iconPost by zezo | 2016-12-11 | 20:26:02
Ooops it was me this time. Made some changes today and psted one line too much and forgot to check if it works at all. Fixed.
Post by iconPost by zezo | 2016-12-11 | 21:49:44


Here is your data with two columns added - speed based on the distance traveled and speed ratio:

153 22 09 52 12 31 22.7 18.4 20.40 1.11
153 27 04 52 14 02 22.7 18.4 20.25 1.10
153 32 01 52 15 33 22.7 18.5 20.35 1.10
153 36 58 52 17 04 22.7 18.4 20.34 1.11
153 41 52 52 18 34 22.6 18.4 20.12 1.09
153 46 44 52 20 04 22.5 18.3 20.00 1.09
153 51 34 52 21 35 22.5 18.2 19.93 1.10
153 56 21 52 23 05 22.4 18.2 19.71 1.08
154 00 32 52 23 08 22.3 18.1 15.33 0.85
154 05 02 52 21 22 22.2 18.0 19.61 1.09

So there seems to be a 10% bonus in your case, and the tacking penalty is more like 20% than 10

Guess it's time to write a robot script to get some stats ...
Post by iconPost by KKAOSS | 2016-12-12 | 01:23:31
zvetan !
just lost the ice exclusion line on your vendee globe buddy! what is happening! yikes
Post by iconPost by Pousstoidlakeuj | 2016-12-12 | 20:57:48
We are again at 106 % and sometime 110 %
Post by iconPost by marcusbelgicus | 2016-12-12 | 23:46:53
I measured it this morning and found that we were around 106 % as well.
Zezo, do you think it would be possible to have that ratio as an input, so one's can test different ratios? Or too much complicated? On Sunday when you changed the ratio at 106 % , it gave me a very different route that came back to the first one when you put the 100 % again.
Post by iconPost by zezo | 2016-12-13 | 12:50:17
Done. "Avoid tacks" replaced with "6% extra speed"
Post by iconPost by marcusbelgicus | 2016-12-13 | 19:30:04
Great! One million thanks Zezo.
Post by iconPost by 92gege56 | 2016-12-13 | 19:05:11
ne serait-ce pas le décalage des 4 à 6 minutes entre la valeur du temps 00, 10, 20, 30,40,50 affichée, et les vrais minutes de calcul 56, 06, 16, 26, 36, 46 qui provoquent ce décalage de 6%?
Encore bravo pour cet outil
Post by iconPost by marcusbelgicus | 2016-12-13 | 20:08:39
I am almost sure the 6 % is an average, in practice the increase is 10 % but for a certain amount of time. Some boats have this bonus, some not. For the moment the boats that are at the front of the race do not have that bonus, but the ones between 1000 (?) and 5000 (? ) has that bonus. In a few hours, I guess that will be another set of boats.
I would not be surprised (but this is just speculation from my side) that the boats that are in front of the race get less often that bonus, the followers more often so the distance between the boats can decrease....and give additional excitement for the followers.
Post by iconPost by zezo | 2016-12-13 | 20:49:57
Right now my performance is below the projection.

One reason for this could be that with the new wind system the wind changes both in time and space, so it matters if you plan the track starting now or with the actual update time in 10 minutes, then the forecast changes over time and so on.

In the end it does not matter very much. 99% of the time those differences don't affect the general strategy, and the uncertainty in the forecast every 6 hours is bigger than 5%, so just sail your boat, watch for rocks and ice limits and don't lose your sleep about about those 5% ;-)
Post by iconPost by jfloviou | 2016-12-14 | 02:52:52
Well, for me right not the route proposed with or without % are TOTALY different .... (one follows the ice limit, second goes north).
And it seems to me that 6% does apply at this time.

If really the "boost" is changing from time to time without warning from VR, that's the worst game change ever: it brings total uncertainty. Impossible to drive the correct route in such situation.

How do you guys know if 6% is on or not ?
Post by iconPost by zezo | 2016-12-14 | 07:32:51
To me it looks like it's just the game engine is using different weather data than the user interface. Wind speeds for the boats are different at the cursor and in the boat info panel, hence the speed difference.

Having the game interface display different winds than those used by the game server is not called a boost. It's called a bug.
Post by iconPost by zezo | 2016-12-14 | 20:02:47
Last night I had few % higher boat speed than advertised. A gybing point placed on the ice limit was advancing almost 1 minute at every 10-minute update cycle. I think a lot of players suffered a penalty because of that.
Post by iconPost by MikeFloutier | 2016-12-15 | 11:39:38
My boat position and heading is the same on both devices...
Post by iconPost by Seche | 2016-12-14 | 19:56:05
Great, great job…
Great, great, great, congratulations !
Post by iconPost by zereguidum | 2016-12-14 | 21:42:08
I do not understand but zezo is giving me completely wrong data for the last 2 days, it is sending me on courses down to the ice zone.
Post by iconPost by BenArfa | 2016-12-14 | 23:22:50
First of all, thank you ZEZO for all your work, you're such a generous man !!
But I have a big probleme since 4 hours. I can't see the position of my boat on ZEZO, there's no routing, there's nothing in fact. I don't understand. I use the google extension on chrome for information.
Thank you for your help
Post by iconPost by zezo | 2016-12-14 | 23:40:53
Hmm have you tried the "Center chart" in the right mouse menu?

The transition across the 180E/W line fails under certain circumstances.
Post by iconPost by Manu-PB | 2016-12-23 | 00:08:37
The green, blue and red forecast lines have disappeared ?
Post by iconPost by Manu-PB | 2016-12-23 | 00:11:25
I appologize. My mistake.
Post by iconPost by bilbo29 | 2016-12-24 | 02:05:03
Hi Cvetan,

I have a question about, the next destination after "Go to CAP HORN" ?
When this new distination will be disponible ?

Thanks, for All Cvetan.
Post by iconPost by marcusbelgicus | 2016-12-24 | 18:36:16
I guess the next point is 'Go to Sables d'Olonnes'. Zezo cannot put a specific point in the Atlantic, it would influence too much the route. You need to select a target yourself I am afraid.
Post by iconPost by bilbo29 | 2016-12-24 | 19:06:55
Hello, marcusBelgicus ou peut être bonjour :o)

Thanks for the answer, and i hope, for you an your family a merry christmas.

And good luck for the end of "The Vendée globe"
Post by iconPost by zezo | 2016-12-25 | 00:15:25
I moved the default destination to Fernando de Noronha again, but the weather is unstable, with at least one (somehow) coastal and one (more) offshore variant.

You should probably pick one of the two at some pint and stick wit it by moving the destination point East or West/Southwest.
Post by iconPost by bilbo29 | 2016-12-25 | 04:22:04
Thanks a lot, for your answer Czetan.

I think that the Return to "les sables d'olonnes" will be not a quietly cruise !!

good luck for your boat, and i wish you a merry christmas.
Post by iconPost by mathfdb | 2016-12-25 | 13:01:57
Hi zezo,

Here's the time if you manage to do it to restore the 16 days option. Coming back in the atlantic, options & strategy are coming back also more than ever .
I know 16days previsions are not good, but we can visualize different options with different destinations point better with 16dayx.

Maybe if it's possible you could stay with the 10 days for " default set" , to be not too eavy for the router, but let us choose 16 days option sometimes?

tks again a lot zezo
Post by iconPost by mathfdb | 2016-12-29 | 10:35:55
Difficulty this morning sometimes to get a direction; changing options ( days, sails, 6% option) sometimes fix the probleme, sometimes not. strange.
Post by iconPost by jago3813 | 2016-12-29 | 11:03:50

This morning, I do not get any route if I do not check "Pro Sails" (which I do not have): any idea?

Post by iconPost by jago3813 | 2016-12-29 | 11:14:20

in fact it depends on the "number of days" selection: for 6 days, it is OK. For 7 (or more): no route.

Post by iconPost by zezo | 2016-12-29 | 17:19:31
The switch in the LAN router went nuts today and broke the connection to one of the load-balancing back-end servers.

As a result of this you would get a blank skreen about 30% of the time.

A simple reload does not cause a new route calculation because of caching strategy, so you have to change something - pro sails, speed bonus, start or end position - to have a new chance to get to the working 70% ;)
Post by iconPost by onyx276ACB | 2016-12-30 | 11:23:14
Hi Cvetan
I wish you my best greetings for the next new year.
I hope you can do this job for a long time.
Yours sincerely.
Post by iconPost by Cyann | 2016-12-30 | 21:56:10
Hi zezo?

Congratulations for your return and this great job.
Glad to see you back with the wonderful add-on in Chrome.
But, yes unfortunatly there is a bug, my way back to France makes me go across Africa, I didn't know these boats could fly over earth.

Post by iconPost by offworld | 2016-12-30 | 22:14:48
Hi zezo,

thanks for share your works..great job!!!!
Post by iconPost by petole | 2017-01-06 | 08:31:38
Hello Cvetan
I can't use the 16 day prediction. It stops at 10. Is it why I am "no pro sail" ? How to get 16 day ?
Post by iconPost by Manu-PB | 2017-01-06 | 18:18:21
The forecast is 10days.
No matter your sails plan.
Post by iconPost by Manu-PB | 2017-01-06 | 18:18:25
The forecast is 10days.
No matter your sails plan.
Post by iconPost by Manu-PB | 2017-01-06 | 18:16:38
10° difference in wind direction @17:10 - 0.44 S - 34.0 W
- Zezo : 113
- Game : 103
I believe in God
Post by iconPost by Manu-PB | 2017-01-06 | 20:07:44
The difference has vanished with wind update @19:05
Post by iconPost by tommmmy | 2017-01-06 | 20:30:20
Merci Manu-PB. en début de parcours, c'était 16 n'est ce pas ?
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