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:

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 #1900
INFO by brainaid.de
Archer 78 PARTICULARS    
WX Updates:
0430 / 1030 / 1630 / 2230    
Ranking: OCQ3 - RWW - OCCH - SUPSOL - SYC
Race starts: Sep 01st 11:00 Registration Open!
▶ Flash
GO TO RACE

SSANZ Triple Series 2025 - Race 3

Welcome to the grand finale of this year's SSANZ Triple Series! The stage is set for the Lewmar 50, a thrilling 39nm challenge tracing the southern shores of the stunning Waiheke Island, pushing out to Tarahiki before the sprint back to Islington Bay. Expect fast legs, tactical battles, and no shortage of drama as our SOLers take on the waters in their Young 88s, lining up once again against the talented IRL members of the Young 88 Association. With the series on the line and everything still to fight for, it all comes down to this final race!
Race #1934
INFO by brainaid.de
Young 88 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
SSANZ - SYC
Race starts: Aug 29th 21:15 Registration Open!
▶ Flash
GO TO RACE

Red Eye - Myth of Malham 2025

In 1947, Hugh McLean & Sons of Gourock, Scotland built a radical racing yacht for John Illingworth, soon-to-be Commodore of the RORC, to a design by Laurent Giles. With a masthead rig, giving her ‘free’ sail area per the rules of the time, and short overhangs reducing pitching, Myth of Malham went on to win The Fastnet that year and again in 1949, and to compete in numerous Admiral's Cups. In 1958, in honour of the yacht, the Myth of Malham race was conceived - a mini-Fastnet to the first lighthouse on a rock west of Cowes, Eddystone, rather than the second, to be held in non-Fastnet years. IRL this year it has been raced already, but this stops us not from “Red Eye” racing its online 230nm in Fareast 31Rs, leaving how to deal with the Isle of Wight open to your own discretion.
Race #1847
INFOby brainaid.de
Fareast 31R PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - RED
RACE CLOSE: Monday,
September 1 at 2300 UTC.
Race starts: Aug 25th 12:00 Registration Open!
▶ Flash
GO TO RACE

Africa by Sea 2025 - Maputo to Mogadishu


The fifth leg of our exploration of Africa By Sea takes us north along the length of the Continent’s succulent sub-tropical and tropical Indian Ocean coast. Much fought over by traders and colonists both well-before and after a Portuguese expedition under the command of Vasco da Gama first sailed there from Europe back in the 16th century, it is yet to be properly explored as a yachting destination. With plenty of islands off- and inshore, small and very large, there is much to interrupt your 1900nm voyage and visit in your Swan 65, from Maputo to Mogadishu! Race #1858
INFOby brainaid.de
Swan 65 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - ABS
RACE CLOSE: Saturday,
September 6 at 2300 UTC.
Race starts: Aug 20th 17:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

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

View full list

Series

Mobile Client

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

The mobile client