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:

Bluefin Tuna - Mexico Gulf to North Sea 2026

Join us and follow the Bluefin Tuna, as they migrate from their spawning grounds in the Gulf of Mexico to their feeding grounds in the North Sea off the coast of Norway. This 4300 nm race is part of our Ocean Championship and the final race of OCQ2 2026, and also the second leg of our Migration series. We will be sailing in our Gunboat 90. Race #2035
INFO by brainaid.de
Gunboat 90 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ2 - MIG - OCCH - SYC
Race starts: Jun 08th 11:00 Registration Open!
▶ Flash
GO TO RACE

Thessaloniki to Port Said 2026

Welcome back to the Eastern Mediterranean for the fifth race of our Magical Mediterranean Series. Only marginally less unlikely to be ever raced in real life during SOL’s lifetime than our previous race from Tobruk to Iskenderun, this 710nm race takes us from Greece’s ancient northern port of Thessaloniki through the Aegean island maze, south east into the Levantine Sea to a finish in modern Port Said, in splendid Swan 65s!
Race #1977
INFO by brainaid.de
Swan 65 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: MED - SYC
Race starts: Jun 06th 15:00 Registration Open!

▶ Flash
GO TO RACE

AWKR 2026


The Australian Women's Keelboat Regatta celebrates and promotes women's sailing in Australia. Comprising a week of intense racing on Melbourne’s Port Phillip Bay, the event has grown to become Australia’s premier women’s regatta and one of the largest in the southern hemisphere, and these past several years Sailonline have been delighted to offer all-comers the opportunity to contemporaneously race against Australia's women virtually in a 20nm round the cans race in Port Phillip Bay. Prepare for some excellent Australian competition! We'll be racing J-109.
Race #2025
INFO by brainaid.de
J-109 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
SPQ2-SPCH-SUPBUD-SYC
Race starts: Jun 05th 02:00 Registration Open!
▶ Flash
GO TO RACE

TuziTekwini TIMED Race 2026

Sailonline is delighted to have been invited again to partner with the King Shaka Yacht Club (KSYC) of South Africa to bring a virtual version of the Tuzi Tekwini Ocean Raceto our online community.
The Tuzi Tekwini Ocean Race is a near 90 nautical mile race down the east coast of South Africa from the port of Richards Bay to the port of Durban. Achievable in a single day and seen by some as an easy mile-builder, the course is more tactical than some think and should not be underestimated. This iconic race promises to be an unforgettable experience for yachting enthusiasts.
Our online version of the race will be 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 #2037
INFOby brainaid.de
Sailonline’s virtual yacht for all your runs will be our much-loved Farr 38 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ2 - TRCH - SUPBUD - SYC
RACE CLOSE: Saturday,
13 June at 23:00 UTC
Race starts: May 31st 12:00 Registration Open!
▶ Flash
GO TO RACE

Susan Hood Trophy Race 2026

Lake Ontario Offshore Racing (LOOR) welcomes racers to Sailonline’s virtual version of their annual Susan Hood Trophy Race. This year, this pleasant weekender on western Lake Ontario will be of about 60nm in length, and online for convenience will start and finish at the Port Credit Yacht Club (PCYC). At or before the real-life Skipper’s Briefing a decision will be made to race the course clockwise (course Delta) or anti-clockwise (Echo). If there is time we will match this online. As before, the race is the first of two that will count towards a special Sailonline's LOOR Series medals, but this year we sail in Jeanneau Sun Fast 3300s. Bon voyage!
Race #2033
INFOby brainaid.de
Sun Fast 3300 PARTICULARS
NAM_AWIP WX Updates:
0245 / 0845 / 1445 / 2045
Ranking: LOOR - SUPBUD - SYC
RACE CLOSE: Friday,
June 5 at 2300 UTC.
Race starts: May 29th 23:45 Registration Open!

▶ Flash
GO TO RACE

Cross the Convergence 2026 - St Helena to Cape Verde


The fourth race of our series of ocean voyages across the World’s convergence zones takes us out of the Pacific into the Atlantic for a 2200nm race in Judel Vrolijk 62’s, from the desolation of St Helena, there where Napolean Bonaparte saw out the end of his life, to the even greater desolation of Fogo in the Cape Verde’s. You’ll have to cross the equator, with the coasts of Africa and South America your only navigational restrictions.
Race #1984
INFOby brainaid.de
Judel Vrolijk 62PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: CCZ - SYC
RACE CLOSE: Saturday,
June 6 at 2300 UTC.
Race starts: May 22nd 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 rafa
  5. Sailonline Yacht Club Member Panpyc
  6. Sailonline Yacht Club Member bonknhoot
  7. Sailonline Yacht Club Member HoratioPugwash
  8. Sailonline Yacht Club Member rumskib
  9. Sailonline Yacht Club Member CollegeFund
  10. Sailonline Yacht Club Member sassy63

View full list

Series

Mobile Client

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

The mobile client