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Board » General Discussion » Velocity made to course

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Posted by
Adam


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2009-01-11 16:55:10
2009-01-22 05:23:40 - Velocity made to course
Is it possible to add this indicator ? Plus miles lost or gained in lets say last 3 hours to the leader ? And mark on the polars the optimum upwind/ downwind angles to VMG ?
Posted by
jakob


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2007-09-04 10:05:30
2009-01-22 07:59:59 - Re: Velocity made to course
Thanks for the suggestion. I will put it on the list but I cannot promise anything soon.
...one of the guys behind the game...
Posted by
Jeroen


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2007-08-15 09:17:47
2009-01-23 14:02:03 - Re: Velocity made to course
We are working on some additional race information.

In the mean time you can find a lot of race info here: http://stenum.se/sailonline/
I am a ex-admin of SOL who joins in from time to time.
Posted by
Impromptu38


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2009-01-04 22:30:14
2009-01-23 19:40:08 - Re: Velocity made to course
Joeron:

The experimental information is just fantastic: Great Work

I will overload my thinking, but I like haveing that information at hand.

Thanks, Ron Casciato, Impromptu38
Posted by
AGage


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2008-12-27 10:31:57
2009-01-25 16:26:56 - Re: Velocity made to course
a6km said @ 2009-01-22 05:23:40:
Is it possible to ..... And mark on the polars the optimum upwind/ downwind angles to VMG ?
================================
If VMG is indeed relevant, you can find the optimum angle quite easily using the steering tool, as it shows you the boat speed and vmg values for various angles as you slowly move the pink 'steering line' to different headings on the map. Note near the bottom right corner of the polar diagram this information is provided. (Hint: look around 42 upwind, and 142 downwind, approx)
Also, it seems to vary very slightly in differing wind strengths, ie from 10 knts to 25.
You can also calculate vmg quite easily with any calculator, incuding the standard Windows one, using the formula: boatspeed * cos(D - twa), where D is 0 for upwind and 180 for downwind, and always use the positive twa (ie if it is actually -140, use 140, although this is really only necessary for downwind calculations.
More specifically twa should be replaced by angle to the rhumbline, but often twa is fine.
Hope this helps...

But one question to the developers of this great software (I am a programmer also).... As the vmg is only displayed to a single decimal point (in the game screen not the polar diagrams), is there any reason to sail at an angle that gives a vmg of, say, 7.43 than 7.47? or is it always rounded (up & down)?
I help develop the client interface for the best online ocean racing sim there is... __/)/)_/)__
Posted by
jakob


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2007-09-04 10:05:30
2009-01-25 21:04:02 - Re: Velocity made to course
Thanks for the feedback!! vmg is rounded only in the user interface. Internally we never round anything. Ohh yea, I think kalle rounds the numbers sent in the commands fom client to server. Hence, twa and cc is not sent to server with more than 2 decimals I think.

/Jakob (one of the developers)
...one of the guys behind the game...
Posted by
Adam


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2009-01-11 16:55:10
2009-01-26 12:53:30 - Re: Velocity made to course
AGage

I know that I'm just saying not everybody understands here what is really going on so an indicator of VMC not VMG is often better because it tells you how fast is the boat traveling to the next waypoint or finish or scoring gate. We know that the straight line is often not the fastest one ... and a lot of people get confused with the VMG as when they reaching the VMG is really small but they sailing so fast so why is it small ? I think it would be nice to have this indicator one day. Cheers.
Posted by
Zembu


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2008-12-15 20:58:27
2009-01-26 14:41:49 - Re: Velocity made to course
Re having VMC, firstly if it were possible, surely this would make it too easy and secondly it would impose a huge burden on the servers as everyone's waypoints (to which their respective VMC's related) would be different.
Posted by
jakob


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2007-09-04 10:05:30
2009-01-26 16:20:00 - Re: Velocity made to course
Hmmm, I think that VMC would confuse sailors too. Imagine the case here you are far from the rounding mark which is almost 90 degrees to your right and you are heading exactly straight to the goal. Your vmc would read almost 0.0 while sailing 25 knots! That will be confusing. Or..
...one of the guys behind the game...
Posted by
erratic


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2008-10-15 19:35:40
2009-01-27 06:25:00 - Re: Velocity made to course
^
There shouldn't be any additional load on the servers - the client could calculate it.

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