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
76Trombones


Users avatar

Posts
362
Registered at
2009-08-03 18:04:56
2012-12-17 00:57:57 - Re: MOD70 polar development
I was playing with the transat data today (will post the grib). The polar that seemed to work well for the European races failed *massively*. Boosted downwind VMG speeds by almost 50% and the tracks snap into place. Insane! Boats go 32 kts average in a pretty wide range of conditions :-)

The Atlantic race gives at least a few good thresholds, as Race For Water was so close, but ended up losing days.
Posted by
76Trombones


Users avatar

Posts
362
Registered at
2009-08-03 18:04:56
2012-12-18 14:13:55 - Re: MOD70 polar development
Here's the Krys race weather. They sure lucked into a fast window!
Attachments
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2012-12-18 16:19:52 - Re: MOD70 polar development
Yoohoo ! :-D

This new weather will be a relief ! I've been fighting against Leg2 for 2 days.... Either best VMG is around Twa 35/37° (which I had never seen before, I believe...) or there's a bug in the position reports and/or the NOAA's gribs... as this is a multihull, I was waiting for a flat polar, with a best VMG at 45 or more.
So far, she looks more like a fighter jet than a sailboat... =-O

Still not convinced about my results, but I'll let you know when I believe I'm close to something "workable"... :-)

As to the race, their average speed is around 30knts !!! That can't be only luck... ;-)
Posted by
LaoziSailor (Han Tacoma-Emons)


Users avatar

Posts
52
Registered at
2011-11-10 00:57:48
2012-12-18 20:21:47 - Re: MOD70 polar development
Tarco, you following me...??
I really don't want to go further S.
We'll see what happens, 2300kn to go, Christmats Morning might have a gift for us :),
Han (aka Laozisailor)
LaoziSailor

Everything gets done by not doing anything!
Posted by
SlashV


Users avatar

Posts
14
Registered at
2009-08-09 22:01:21
2012-12-18 22:21:52 - Re: MOD70 polar development
I'll have a go at creating the polars as well and maybe we can compare or average later.

Will probably have some time during christmas :)

Data and results will go here


--- Last Edited by Jaap Versteegh at 2012-12-18 23:51:47 ---
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2012-12-18 23:51:52 - Re: MOD70 polar development
FANTASTIC !!!!

The new ocean grib file you made works on Ugrib, so I can check the wind when and where I need it , without dowloading 8 files per day, providing only the possibility to check exclusively the first minute of each....

Thank you very-very much !!! :-D
Posted by
Tarco


Users avatar

Posts
41
Registered at
2011-11-09 21:54:22
2012-12-19 14:21:52 - Re: MOD70 polar development
Hi,all !
Finishing the Ocean samples... More than 1000 of them...
This time, they are extremely precise ! :-)

It seems Race for Water had a pb, as if they couldn't use their gennaker, or something like that. For every sample, their speed was 5 to 10 knts lower than the others in the same conditions.
Oman probably had problems too : after they drifted south; their speed was never as high as the others'.

Best VMG : around 165 between 16 and 20knts TWS !!!
Max BS : 33 (averaged)

Polar goes up and down, probably depending on the sail they use and if they can sail on one hull or not...
Huge gap around TWA 100-105, below 10knts TWS. And another one at TWA 150, at TWS22 and above...

More news when I'm done with Leg 1... again.
I want to have the polar as complete as possible bafore I "publish" it. ;-)
Posted by
SlashV


Users avatar

Posts
14
Registered at
2009-08-09 22:01:21
2012-12-21 14:33:03 - Re: MOD70 polar development
The track logs of the races I found contain position data that is already transformed to the addviso maps, it seems.

Does anybody know where to find lat,lon positions for the Krys and European tour races?
Posted by
76Trombones


Users avatar

Posts
362
Registered at
2009-08-03 18:04:56
2012-12-21 18:12:27 - Re: MOD70 polar development
Hey awesome! Anyone else want to join in as well? Impressively organised - "polar" opposite of my desk :)

They're giving x/y coordinates with origin at upper left. For the Krys race, using a starting lon of 150.312 (map edge) seems to line up the data, though you end up with a funny multiplier (123.55).

You normally expect to end up with nice clean numbers (120 makes sense) so I've probably messed up somewhere.

For the y direction I get ~81N as origin and multiplier of ~167, which not only doesn't match the x scaling but also the bounds of the map.

But it's something like that. The other xml file contains all the x/y values for the race waypoints and features. Which make figuring out the scaling easier as you have clearly defined points.

(here's what I have so far - mostly featureless blob, but "races" pretty fairly against the real boats. Will be interesting to see how the different approaches compare!)



--- Last Edited by 76Trombones at 2012-12-21 18:18:36 ---
Attachments
Posted by
SlashV


Users avatar

Posts
14
Registered at
2009-08-09 22:01:21
2012-12-21 18:32:11 - Re: MOD70 polar development
Ah thanks, was hoping I could avoid having to figure out the transformation from map coords to lat/lon, but since you did it as well I guess that's the way to go. Will do that then :)

Thanks as well for your results so far. "Featureless" would not really surprise me for this kind of boat.
I am not an expert, but the narrow hulls will likely have a boring resistance curve and at the speeds they do, they'll pretty much have just one sail configuration for any true wind angle: close-hauled :D
..as well as high lift/drag ratio's -> low angles of attack -> linear performance

--- Last Edited by Jaap Versteegh at 2012-12-21 19:18:20 ---

Page: Previous 1 2 3 4 Next

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

New Ice Age 2026 - Browerville to Longyearbyen


Our 2026 long-distance ice-boating challenge continues with a second race in Arctic waters, now from Browerville, where we arrived less than a month ago, continuing east, back to Svalbard’s Longyearbyen, leaving Canada’s Ellesmere Island to port and Denmark’s Greenland to starboard. It’s about 2500nm, which, if there’s wind at all, should, well-wrapped in your DN-cockpits, not take you more than a day or three, thus to complete your first (of several) online circumnavigation of the planet of 2026!
Race #1969
INFOby brainaid.de
DN PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: NIA - SYC
Race starts: Feb 19th 07:00 Registration will open soon
▶ Flash
GO TO RACE

Doha Basra TIMED Race 2026

Welcome to Kuwait for a short 78 nm TIMED race from the port of Doha (not to be confused with Doha, Qatar) to Basra, Iraq. Jazirat Light on Auha Island is the only mark to observe, leaving it to port. The Beneteau First 40.7v2 racer-cruiser is our ride this month. This is a TIMEDrace so you may RE-REGISTER HEREto try again after finishing a run. You will have 13 days and 11 hours to test your skill and decision making after the race opens.
Race #2008
INFOby brainaid.de
First 40.7v2 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ1 - TRCH - SYC
RACE CLOSE: Saturday,
28 February at 23:00 UTC
Race starts: Feb 15th 12:00 Registration Open!
▶ Flash
GO TO RACE

San Diego Islands Race 2026


Sailonline is proud to once again partner with the San Diego Yacht Club for the annual Islands Race! This iconic offshore challenge spans approximately 140 nautical miles, starting in Long Beach, rounding the Catalina Islands, and finishing in San Diego. Shifting coastal winds and tactical island roundings will test every sailor’s judgment and nerve.

This year, our SOLers will race the Ker 40, a proven high-performance design by Jason Ker and built by McConaghy Boats. Fast, responsive, and demanding, the Ker 40 rewards precision and smart strategy. The competition will be tight. Every decision will count. See you on the start line!
Race #2009
INFO by brainaid.de
Ker 40 PARTICULARS
NAM_AWIP WX Updates:
0245 / 0845 / 1445 / 2045
Ranking:
SUPBUD - SYC
Race starts: Feb 13th 20:00 Registration Closed
▶ Flash
GO TO RACE

Cross the Convergence 2026 - Samoa to Hawaii


The second race of our new series of ocean voyages across the World’s convergence zones, takes us northward again up the Pacific Ocean, now from Samoa at 13.5 degrees South, across the Equator to Hawaii, famed for its breaking surf and active volcanoes, on the edge of the Tropic of Cancer at 19.5 degrees North. It’s 2300nm, so we’ll take our very steady Steinlager II. Race #1982
INFOby brainaid.de
Steinlager IIPARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: CCZ - SYC
RACE CLOSE: Saturday,
February 21 at 2300 UTC.
Race starts: Feb 06th 18:00 Registration Closed
▶ Flash
GO TO RACE

Beketov by Balloon 2026 - In Siberia


Way-back-when France and England, and Spain as well, were squabbling about who should control what of North America, only to lose the most of it to their own insurging colonists, their eastern European neighbour empire, Russia, was quietly assimilating vast, thinly nomadically populated territory of its own – Siberia! Amongst the many explorers and adventurers that served Russia so well in these conquests was the Cossack hetman Pyotr Beketov. Let’s pretend we’re he and eschewing horseback, let’s travel by balloon from Yekaterinberg to Krasnoyarsk – just a short 2000km (1100nm) section of the Trans-Siberian Express’ 9289km!
Race #1972
INFOby brainaid.de
SOL Balloon PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: BOL - SYC
Race starts: Feb 03rd 13:00 Registration Closed
▶ Flash
GO TO RACE

West Papua to Oregon 2026

Our next race in our Ocean Championships is the first of a series of great natural migrations we will track in 2026. The leatherback turtle is the most widely distributed marine reptile on planet Earth, and chooses to breed in warm tropical waters, but prefers to forage in more temperate habitats, travelling thousands and thousands of miles effortlessly annually to maintain this way of life. Our race will follow one of the typical trips of this turtle, from breeding grounds in the seas off West Papua to the coast of Oregon. It’s only 5900nm, so to keep up, but in comfort, we’ll follow in our Gunboat 90.
Race #2006
INFO by brainaid.de
GB 90 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ1 - OCCH - MIG - SYC
RACE CLOSE: Tuesday,
February 24 at 2300 UTC.
Race starts: Feb 02nd 11:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member KaSToR
  2. Sailonline Yacht Club Member WRmirekd
  3. Sailonline Yacht Club Member CriticalHippo
  4. Sailonline Yacht Club Member rafa
  5. Sailonline Yacht Club Member rumskib
  6. Sailonline Yacht Club Member Sax747
  7. Sailonline Yacht Club Member vida
  8. Sailonline Yacht Club Member CollegeFund
  9. Sailonline Yacht Club Member bonknhoot
  10. Sailonline Yacht Club Member BRENTGRAY

View full list

Series

Mobile Client

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

The mobile client