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 » Wrong Speed VMG

Page: 1 2 3 4 Next

Posted by
trev


Users avatar

Posts
4
Registered at
2008-11-09 19:33:09
2008-12-27 00:17:54 - Wrong Speed VMG
I have set a course in the Sydney/Hobart race with a BS of 20.17KTS and a VMG of 17.10 but when the boat changes to that course the boat is only doing 18.9KTS and a VMG of 15.9. This dosen't look right to me.
Posted by
jakob


Users avatar

Posts
364
Registered at
2007-09-04 10:05:30
2008-12-27 06:41:22 - Re: Wrong Speed VMG
Well, I have checked the vmg-predictor and the actual vmg without finding any bugs... Please keep reporting if you see that behaviour in the future.
Regards
Jakob
...one of the guys behind the game...
Posted by
NZL_PaulR


Users avatar

Posts
311
Registered at
2008-07-22 12:21:30
2008-12-27 07:00:14 - Re: Wrong Speed VMG
Perhaps your performance wqas not back up to 100%; hence lower speed until you recovered from lots of tacks or gybes
If it breaks, it's not strong enough!
Posted by
jakob


Users avatar

Posts
364
Registered at
2007-09-04 10:05:30
2008-12-27 07:33:43 - Re: Wrong Speed VMG
YES, thats most likely the reason. Thanks! :-)
...one of the guys behind the game...
Posted by
trev


Users avatar

Posts
4
Registered at
2008-11-09 19:33:09
2008-12-27 09:49:36 - Re: Wrong Speed VMG
Yes I actually think you are right. Looked back about 5 mins after course change and the figures seemed right.
:)
Posted by
NZL_PaulR


Users avatar

Posts
311
Registered at
2008-07-22 12:21:30
2008-12-27 10:14:47 - Re: Wrong Speed VMG
And if you are on a steady course, your speed will increase a little more, and a little more and more, whilst still PERF% is 100%.

See good hhelming is essential, rather than writing your name in the ocean! LOL
If it breaks, it's not strong enough!
Posted by
zerl


Users avatar

Posts
5
Registered at
2008-11-01 16:45:22
2008-12-29 16:59:44 - Re: Wrong Speed VMG
I'm curious: does the increase in speed apply to both CC and TWA?
Posted by
kalle


Users avatar

Posts
413
Registered at
2007-06-01 09:58:04
2008-12-29 17:03:30 - Re: Wrong Speed VMG
I'm not sure if you misunderstood what Paul meant. When doing a course adjustment you will get lower performance for a certain period (shown in the "Performance" instrument in the client). If you don't do any further adjustments the performance will rise to 100% percent, but if you do another tack etc, it will drop again. Both adjustments using CC and TWA count.
Posted by
StuArt


Users avatar

Posts
118
Registered at
2008-11-15 22:03:54
2008-12-31 17:37:59 - Re: Wrong Speed VMG
Hi Kalle, Jacob e.a.

I understand the performance decrease and I agree with it :-)

But sometimes it seems not to be very realistic - for example when I gype, what can give me in real life a push when well done rather than a disadvantage. So playing with wind shifts could be not wise because of the decrease in performance.

Posted by
jakob


Users avatar

Posts
364
Registered at
2007-09-04 10:05:30
2008-12-31 19:02:03 - Re: Wrong Speed VMG
Well, we need to implement a good-enough rule that works for all boats, all conditions and at all times so I am very sure that it sometimes might be a little unrealistic. If you have suggestions on how to model the impact on performance from maneouvers- please just let me know and we will really concider it :-)
...one of the guys behind the game...

Page: 1 2 3 4 Next

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

ORCV Melbourne to Hobart 2024


Welcome to the legendary "Westcoaster," a race that has tested sailors for over 50 years. Spanning 435 nautical miles, this iconic journey takes racers from Melbourne, across the formidable Bass Strait, and around Tasmania's rugged west coast to the finish line in Hobart. Organized by the Ocean Racing Club of Victoria, the Westcoaster is renowned for its challenging conditions and adventurous spirit. This year, our SOLers will tackle the course in the swift and capable First 47.7, a yacht launched by Beneteau in 2000, built for speed and endurance in long ocean races. Get ready for an exhilarating ride in one of Australia’s most celebrated yacht races!
Race #1841
INFO by brainaid.de
First 47.7 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC
Race starts: Dec 26th 23:00 Registration Open!
▶ Flash
GO TO RACE

Tasman Double 2024 - Sydney to Hobart

Christmas in Summer? Ah yes, we are in the southern part of our globe. Moment, 26 December is St. Stephen,'s Day known also as Boxing Day. To celebrate this day SOL invites you to race your Super Maxi 100 in the traditional 625nm run from Sydney to Hobart. This race is Leg 1 of our Double across the often-stormy waters of the Tasman Sea.
Race #1876
INFO by brainaid.de
Super Maxi 100 V2 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: TD - SYC
Race starts: Dec 26th 02:00 Registration Open!
▶ Flash
GO TO RACE

Refeno Rally 2024


Although since 1986 this 300nm course from Recife, Brazil, to Fernando Noronha Island has been run many times IRL, we have only used this route twice in SOL. This time it will be the route of the last race in the ARCH 2024 classification.
Although the winner of the general classification can already be determined, the fight for the next places on the podium should be fierce. There are several contenders and Dofour34 have them at their disposal. Since we are starting in Vida_Maldita's home waters, he will give us a 30-minute handicap. Or maybe we should give it to him? 😊
Race #1865
INFO from brainaid.de
Dufour 34 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
ARQ4 - ARCH - SUPSOL - SYC
RACE CLOSE: Monday,
December 30 at 2300 UTC.
Race starts: Dec 23rd 17:00 Registration Open!
▶ Flash
GO TO RACE

Tristan da Cunha TIMED Race 2024

Originally designed by NZL_Scotsman, we head for the remote outpost of Tristan da Cunha where gales and storms may come and go but the sea is everlasting. This 64nm TIMED race has been raced on several occasions before, and this time we will be doing it in Rustler 36s.
RE-REGISTER HERE to race again after finishing a run
Race #1875
INFO by brainaid.de
Rustler 36 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ4 - TRCH - SUPSOL - SYC
REGISTRATION CLOSE: Saturday, 28 December at 22:00 UTC
RACE CLOSE: Saturday, 28 December at 23:00 UTC
Race starts: Dec 15th 12:00 Registration Open!
▶ Flash
GO TO RACE

The Beagle in the Azores 2024


And west the Beagle went one final time to round the Cape of Good Hope on May 31 1836. Ashore, Darwin met up with the Astronomer Royal, Herschel, who just happened to be in South Africa at the same time mapping the southern skies. After sounding out his many ideas on evolution and extinction with Herschel, the Beagle now sailed north, stopping briefly in St Helena, Ascension and Brazil, and the Cape Verdes again, to reach the Azores on September 19, 1836. Fitzroy and Darwin at this stage were in a hurry to get back to Britain, but online in 2024 we will stay a little longer to explore this final remote archipelago in our virtual Tall Ship Class B Beagle, 630nm round and about the islands, minding as always in these waters not to bump into any large cetaceans!
Race #1758
INFOby brainaid.de
Tall Ship Class B PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SVF - SYC
RACE CLOSE: Friday,
December 27 at 2300 UTC.
Race starts: Dec 14th 13:00 Registration Closed
▶ Flash
GO TO RACE

Christmas(W) to Christmas(E) Island 2024

Two waypoints, start and finish, and between them 5827 NM of two oceans. Not much time if we want to sit at the Christmas Eve table. You will need to maintain an average speed of over 10 knots, so prepare your 90ft well and choose the best of the many possible routes. Hands up everyone who knew there were TWO Christmas Islands?! OK, maybe you have sailed this Sailonline course before... but it's time to get ready for the 2024 challenge of a reversed race, starting in the Indian Ocean, racing to the Christmas Island in the Pacific! It also marks the conclusion of our prestigious Ocean Race Championship 2024. Please have fun! Fair winds!
PRIZE: SMPF
Race #1868
INFO by brainaid.de
90ft Monohull PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ4 - OCCH - SUPSOL - SYC
RACE CLOSE: Saturday,
January 4 at 2300 UTC.
Race starts: Dec 02nd 11:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member WRmirekd
  2. Sailonline Yacht Club Member FreyjaUSA
  3. Sailonline Yacht Club Member CriticalHippo
  4. Sailonline Yacht Club Member Vida_Maldita
  5. Sailonline Yacht Club Member rafa
  6. Sailonline Yacht Club Member Satori
  7. Sailonline Yacht Club Member Kipper1258
  8. Sailonline Yacht Club Member Sax747
  9. Sailonline Yacht Club Member BRENTGRAY
  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