Facebook

Login

Support Sailonline

If you haven't already - join the SAILONLINE YACHT CLUB!

Please also consider making a donation - all amounts are greatly appreciated!

Board » General Discussion » MOD70 polar development

Page: Previous 1 2 3 4 Next

Posted by
SlashV


Users avatar

Posts
14
Registered at
2009-08-09 22:01:21
2012-12-26 00:33:49 - Re: MOD70 polar development
I've made the following approximation for the krys map:
lat = -2.855E-7 * x^2 - 0.002296592 * x + 69.251568
lon = 0.008093847 * y - 150.31126
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2012-12-26 00:51:55 - Re: MOD70 polar development
This is my first draft : a BWR polar
I think timings are close to what happened, except in Euro-Leg 4, trajectories are not always right, though....
It still needs some corrections.

Don't use for navigation !!! :-)

--- Dernière modification par Tarco le 2012-12-26 00:52:59 ---
Attachments
Posted by
SlashV


Users avatar

Posts
14
Registered at
2009-08-09 22:01:21
2013-01-13 04:24:06 - Re: MOD70 polar development
OK, found some time :) and created a script to parse the addviso xml files and 'enrich' the results with data from the grib files.
I will try to come up with a least squares fit for curves to match the data. Anyone know good basis functions for this?
I am curious how this will turn out. The data doesn't look particularly 'neat'. I attached some plots.
@Tarco. I'll have a look at your file as soon as I have some results of my own.
Attachments
Posted by
76Trombones


Users avatar

Posts
362
Registered at
2009-08-03 18:04:56
2013-01-14 15:28:00 - Re: MOD70 polar development
Those look great. Immediate impressions are of deeper vmg downwind and even more light wind speed. It looks like there are interesting things going on headsail reaching as well.
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2013-02-07 20:09:44 - Re: MOD70 polar development
Back after a month...
Is it only me ? I don't have access to Krys Ocean race tracker anymore...

My impression : when they pinch (TWA35), they are able to keep the speed they have build. When they haven't build the speed, they stay at half-ish the top speed they can reach.
That makes 2 sets of speed at low TWA. One set at almost twice the wind speed when they have build the top speed, coming from higher TWA and another set of "low" speed when the speed is not built yet... don't know if I'm clear...
That could probably be simulated by keeping the high speed with a huge loss of speed (50 % or so) when tacking at TWA 50 or less. Or maybe take a top speed of 3/4 of sample speed...

Back to sampling Euro Tour before it disappears too... New results in a few days.
Next races will be in june (Euro Tour) then October 2013 (World Tour in legs)

Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2013-04-18 21:04:42 - Re: MOD70 polar development
Back again...
All the trackers have disappeared, so I can't go on with the calcs....

Here are the results I got, up to now. (see attached)

Between brackets, the number of occurences.
When I found several results, too different one from the other, I kept both.

I hope a polar can be created from that.
Attachments
Posted by
76Trombones


Users avatar

Posts
362
Registered at
2009-08-03 18:04:56
2013-04-18 22:12:00 - Re: MOD70 polar development
Looks good Tarco - I think we probably have enough data for a good guess. I can help bring it all together, or would you like to do the honours?

They'll be racing the "Route des Princes" in June as 4 shorter legs around Europe. We might not be able to fit all legs in (though it would make a nice series). RC probably has an idea of what's on deck for June, but it's always a busy month. Even if we don't do them in SOL we can "race" the new polar as a final check.

The *big* race will be the Transat in November? I hope they all make it to the start.
Posted by
RainbowChaser


Users avatar

Posts
2656
Registered at
2009-06-14 09:44:50
2013-04-18 22:30:18 - Re: MOD70 polar development
The SOL Racing Year shows what we have pretty much committed to in June .. it is a busy month... but if you can find a way to fit these new races in please feel free to do so! I am all for new ventures :-)

Are the races already in bed with a virtual sailing platform? If so, then that is another issue to be "managed" :-)
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2013-04-19 09:04:39 - Re: MOD70 polar development
I would really love to build the SOL polar.

As June is already overbooked, we should probably not try to run the Princes races. But we can use them to compare the "predicted" speeds to the real ones. They will probably publish a real time tracker on line.
Probably a good way to make corrections to the 'prototype'.

Then, maybe, run a short race in September as a warm-up for crews before the Atlantic race in November. The polar should be ready by then.

The only problem is that "How to create SOL polar for dummies" is not published yet... :-)
I'll probably (certainly) need some help... :-)
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2013-04-24 06:20:19 - Re: MOD70 polar development
76T, on second thought, I reckon you should create the "guessed" polar, so we could try it on a short race in may. And compare it to the real "Route des Princes" legs in June.

I believe that would take you a few hours when I would need weeks, if not more, just to understand how to do...

But I would like you to explain me afterwards, if you've got time to. :-)


--- Dernière modification par Tarco le 2013-04-24 09:49:59 ---

Page: Previous 1 2 3 4 Next

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

Chinook Salmon - Canada to Andreanovs


A year after spawning in the upper reaches of the rivers of British Columbia, Chinook Salmon develop the age-old urge, so familiar to SOLers, to go to sea, heading for different parts of the northern Pacific Ocean. This race catches up with a particular school with an instinctive memory for the Andreanov Islands far west on the Aleutian Islands chain, as they depart the Salian Sea between Vancouver Island and the San Juans. It’s 2200nm and we’re taking the 60ft Trimaran, in the hope we can keep up!
Race #2048
INFOby brainaid.de
60ft Trimaran PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: MIG - SYC
Race starts: Jul 21st 11:00 Registration will open soon
▶ Flash
GO TO RACE

Juventud TIMED Race 2026

Welcome to Isla de la Juventud (Isle of Youth), Cuba’s second largest island after mainland Cuba. Known as a haven for pirates, the island was the inspiration for novels “Treasure Island” and “Peter Pan”. The circa 120nm course runs clockwise around the island.
This is a TIMEDrace so you may RE-REGISTER HEREto try again after finishing a run. You will have two weeks to test your skill and decision making after the race opens.
Race #2049
INFOby brainaid.de
The boat for this race is the sporty Mini 6.5p Foil PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ3 - TRCH - SYC
RACE CLOSE: Saturday,
1 August at 23:00 UTC
Race starts: Jul 19th 12:00 Registration will open soon
▶ Flash
GO TO RACE

Tall Ships 2026 - Antwerpen to Stavanger


Welcome to the third of four virtual Tall Ships Races in European waters which are concurrently being organized in-real-life by Sail Training International . This third race is from Antwerpen back up the North Sea to Stavanger in Norway – another proper tall ship training adventure of circa 450nm, online again in Sailonline’s classic Clipper 240.
NOTE: Starts and Finishes in tall ships racing are always offshore to avoid conflict with shipping and shipping lanes; online and real-life may not match exactly.
Race #1994
INFO by brainaid.de
Clipper 240 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: TSI - SUPBUD - SYC
Race starts: Jul 14th 16:00 Registration Open!
▶ Flash
GO TO RACE

Lake Ontario 300 Challenge 2026

Lake Ontario Offshore Racing (LOOR) welcomes Sailonline sailors to a second virtual version of a race in their annual series, and for the sixth year in succession the LO300. As the name implies, the LO300 is a 300nm offshore race across the length and breadth of Lake Ontario, from and back to Port Credit YC. This year, for the first time, we will be racing the 300nm circuit in Sun Fast 3200s. As usual, there is an overall prize for the SOLer who best bosses Lake Ontario over the two races hosted by Sailonline, this LO300 and the Susan Hood raced back in May, and this year also the race and the Susan Hood count towards the title of Super Buddy 2026; so, let the competition be fierce!
Race #2044
INFOby brainaid.de
Sun Fast 3200 PARTICULARS
NAM_AWIP WX Updates:
0245 / 0845 / 1445 / 2045
Ranking: LOOR - SUPBUD - SYC
Race starts: Jul 11th 15:10 Registration Open!

▶ Flash
GO TO RACE

Alaska to Easter Island 2026

Welcome to yet another all-new series. The initial leg of the RNW (Round the New World), Alaska to Easter Island, also part of our Ocean Championship. The first race of OCQ3 2026. This race will be sailed in our revised 'version 2' Imoca 60 Foil. Race #2042
INFO by brainaid.de
Imoca 60 Foil v2 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ3 - RNW - OCCH - SYC
Race starts: Jul 06th 11:00 Registration Closed
▶ Flash
GO TO RACE

Cross the Convergence 2026 - Sao Tomé to Tristan

The fifth race of our series of ocean voyages across the World’s convergence zones takes us back south down the Atlantic from Sao Tomé on the Equator to Tristan da Cunha on the edge of the Roaring Forties. It’s 2500nm; in your path the Benguela winds and current along the south west African coast, and behind that the St Helena High stretching halfway to South America. So, mind where you go in your Volvo OD65 version 3 (based on sampled real-life race data by kroppyer)!
Race #1985
INFOby brainaid.de
Volvo OD65v3 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: CCZ - SYC
Race starts: Jul 03rd 18:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member WRmirekd
  2. Sailonline Yacht Club Member KaSToR
  3. Sailonline Yacht Club Member CriticalHippo
  4. Sailonline Yacht Club Member Panpyc
  5. Sailonline Yacht Club Member cdhinman
  6. Sailonline Yacht Club Member bonknhoot
  7. Sailonline Yacht Club Member rafa
  8. Sailonline Yacht Club Member CollegeFund
  9. Sailonline Yacht Club Member ms0689
  10. Sailonline Yacht Club Member rthinman

View full list

Series

Mobile Client

SYC members have the benefit of access to our mobile/lightweight web client!

The mobile client