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:

Silverrudder 2025


Ahoy, SOLers! Get ready for the epic Silver Rudder – Challenge of the Sea! This 125nm single-handed race around Denmark’s island of Funen is back—shallow waters, narrow straits, and shifting winds await. This year, we trade up to our single-handed X-99s—can you master their power where precision counts most? It’s the world’s largest solo regatta, and your virtual helm is calling! Chart your course, trust your instincts, and race for glory in this ultimate test of seamanship!

It is imperative that you read AND understand these special Starting Conditions for SILVERRUDDER 2025:
Starting Conditions!!
Race #1948
INFO by brainaid.de
X-99 Single-handed PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC
Race starts: Sep 19th 09:00 Registration Open!

▶ Flash
GO TO RACE

Rome to Tripoli 2025


The next race in the ARCH series will take us almost straight from Rome to Tripoli. But don't expect this 550nm race to be an easy one. The Mediterranean always offers some surprises. So let's prepare your Lagoon 55 with due care and... Fair Winds.
Race #1943
INFO from brainaid.de
Lagoon 55 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
ARQ3 - ARCH - SUPSOL – SYC
Race starts: Sep 15th 17:00 Registration Open!
▶ Flash
GO TO RACE

Carib Rum Run 2025

Welcome to the Caribbean and Sailonline’s legendary Carib Rum Run! This year we trade tall ships for pure speed as we race our sleek Santa Cruz 70s on a 1759nm slalom through the rum islands. Yer mission: plunder barrels from the region’s finest distilleries and deliver ‘em to the rum-thirsty sands of Cancun, Mexico. Finish on or before International Talk Like a Pirate Day, 19 September, to etch yer name in legend! Join SYC before race end and ye scallywags can disguise yer boat with a pirate name for this race only! Hoist the sails, sharpen yer cutlasses—the rum run awaits!
Race #1944
INFO by brainaid.de
Santa Cruz 70 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC
Race starts: Sep 15th 00:00 Registration Open!
▶ Flash
GO TO RACE

Roslagen TIMED Sea Race

Welcome to quite possibly the most challenging TIMED race of the year. This month finds us in Sweden with lots of islands and narrow passages when we sail our Seacart 30 trimaran over the 86nm from Lidingö outside Stockholm to the beautiful coastal village of Öregrund. Consider yourself a winner if you complete the course nonstop! 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 #1945
INFO by brainaid.de
Seacart 30 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ3 - TRCH - SUPSOL - SYC
Race starts: Sep 07th 12:00 Registration Open!
▶ Flash
GO TO RACE

Great Nicobar to Marion Island 2025

The Adventure Continues – Leg #6 of the RWW Series.
We’re setting sail on the next stage of the RWW Series: a 4,400-nautical-mile passage from Great Nicobar to Marion Island. This demanding leg will test endurance, strategy, and seamanship at the highest level. As part of the 2025 Ocean Championship, this marks the ninth legendary challenge in the series — and one of the most exhilarating yet. The race will be contested aboard the Archer 78’ ketch, a vessel built to push sailors to their limits across the vast Indian Ocean.
PRIZE: SMPF
Race #1942
INFO by brainaid.de
Archer 78 PARTICULARS    
WX Updates:
0430 / 1030 / 1630 / 2230    
Ranking: OCQ3 - RWW - OCCH - SUPSOL - SYC
RACE CLOSE: Thursday,
September 25 at 2300 UTC.
Race starts: Sep 01st 11:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member vida
  2. Sailonline Yacht Club Member WRmirekd
  3. Sailonline Yacht Club Member CriticalHippo
  4. Sailonline Yacht Club Member rafa
  5. Sailonline Yacht Club Member KaSToR
  6. Sailonline Yacht Club Member Kipper1258
  7. Sailonline Yacht Club Member BRENTGRAY
  8. Sailonline Yacht Club Member Sax747
  9. Sailonline Yacht Club Member Panpyc
  10. Sailonline Yacht Club Member CollegeFund

View full list

Series

Mobile Client

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

The mobile client