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    Posted: 05 Sep 13 at 5:37pm
What these basically tell you is what angles you should be sailing at.

So, for example, if Peaky's curve for the RS100 is correct then if your round the cans course has a leg of 112 degrees from wind direction, then you should sail roughly half of it on a beam reach at 8 knots, and half with the kite up at 12 knots, rather than point straight at the mark at 5 and a half knots whinging about how terrible the courses are at your club...
The trouble is that getting the angles right, exploiting the gusts etc is difficult (and thus easy to get horribly wrong) whereas pointing at the mark is easy.

Edited by JimC - 05 Sep 13 at 5:39pm
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i tick View Drop Down
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Post Options Post Options   Quote i tick Quote  Post ReplyReply Direct Link To This Post Posted: 05 Sep 13 at 6:39pm
I dont really care. I aim at the mark and then bear away until it feels fast enough without missing the mark. Everyone passes me and I am last. I can guarantee that If I learn about vectors, polars and VM blinkingG's I will still be last. Once an idiot always an idiot. 
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Post Options Post Options   Quote Koops Quote  Post ReplyReply Direct Link To This Post Posted: 05 Sep 13 at 6:58pm
Jimc: I think that u have just explained something that has been a mystery to me for a long time.
Years ago a chap who was regarded as 'pot hunting' borrowed a Vareo when the class was quite new and competed in a class event. I recall us being well bunched at the windward mark, hoisting spinnakers and heading off generally in same direction. However the borrower sailed much higher, off to the side of the course, hoisted and finished at the leeward mark far ahead of everyone else. I was greatly impressed at how he had managed to spot a pat h of breeze at such a distance, but am now thinking that he was much more skilled at boat polars. Thank you!
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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 05 Sep 13 at 7:13pm
Originally posted by i tick

Originally posted by iGRF

Someone start a thread about polars, I never understood them either..

That's the trouble with dinghyists all so up themselves hardly anyone knows anything yet they all pretend to understand, then say nothing for fear of sounding an idiot, so it's left to us actual idiots who don't care, to ask.

Well thank you young man, like I said Emporers new clothes. I now have a rough idea of what VMG means but I do not think it will improve my performance much on Sunday. When the 'Boy' gets back from Australia in a few weeks I will explain it all to him but I have an idea he may tell me to stick my V.M.G. up my B.U.M.


As you know, I've raced against your boy, and I can safely say he has as good a natural knowledge of VMG as anyone else I've ever seen. How he computes it is another matter - I've no idea if he reads up on such stuff, makes notes etc, or just has excellent feel for what is going on - either way, he is using VMG.
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Post Options Post Options   Quote i tick Quote  Post ReplyReply Direct Link To This Post Posted: 05 Sep 13 at 7:44pm
Thank you Rupert, however i am not sure he can read at all.....I do not deny that I am proud of him. After winning the Bytes at Sailfest he came to the club last Sunday late when he should have been packing for Australia. There was a spare Supernova for the last race. It was very windy and he has not touched a nova for at least a year. He dropped it in twice before the start and went off late but on one long close reach he took two boats by going low then hardening up. VMG? At the end he was way ahead of all the Novas and on the back of a 300. He won on PY massively. 

Anyone got a good Streaker to lend for next years Nationals?
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sargesail View Drop Down
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Post Options Post Options   Quote sargesail Quote  Post ReplyReply Direct Link To This Post Posted: 05 Sep 13 at 11:28pm
Originally posted by cad99uk

Originally posted by Rupert

I'm not a yottie, but I have read articles where they are talking about knowing that is a certain breeze, a certain boatspeed will give best vmg, so they will bear off from the highest angle they can sail until they have that boatspeed. I guessing this is done by spending a lot of time practicing and taking readings, and I would imagine is still only a rough guide.


Reference to a boat's polars helps here too.

Reference to what's going on around you helps too!  I was asked to sail to target speeds (which are derived from the polars) once......but it felt wrong (ie not best VMG).  Sure enough when I asked to be allowed to sail it dinghy fashion by feel, we jumped forward in the fleet.  Kind of suggested they needed to re-write the polars and target speeds.  Conditions were not extreme - no big waves or tide to skew.

But the bigger you go the more its about the mechanics of sail and hull, and less affected by other factors.
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 06 Sep 13 at 8:46am
So, are these 'polars' available for different boats, when was that one issued for the RS100? Where can I order one for the Alto and the EPS?

Then the next question (blindingly obvious even to an idiot) if there are such things, that are calculated on fact rather than anarchic fiction like club returns, why is it so difficult to have a given boat a permanent handicap calculated for it?
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Post Options Post Options   Quote Noah Quote  Post ReplyReply Direct Link To This Post Posted: 06 Sep 13 at 9:08am
Polars are rarely - if ever - available for dinghies because they are affected to a much greater degree than lead-mines by waves and crew mass. Also, I know of no class where the carrying of electronic aids is permitted (TacTic excluded), so you don't know how fast you're going anyway.
I also assume that the theoretical polars determined by the designer will be modified by on-the-water experience into a 'real' set. (e.g. Do It Yourself!).
Finally, race lengths come into it too. A tiny speed advantage over 24 hours can amount to significant distance. One fluffed tack will have a much greater impact in a 15 minute upwind dinghy leg. 
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Post Options Post Options   Quote alstorer Quote  Post ReplyReply Direct Link To This Post Posted: 06 Sep 13 at 9:24am
Pretty sure i14s let you carry whatever electronics you want?
 
Some classes allow you to carry GPS tracking devices as long as there's no visible readout whilst sailing
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 06 Sep 13 at 9:38am
I assumed that compass thing with the electronic read out that some folk use did all that, why would it restrict itself to just compass angle degrees? Anyone can wear a wrist mounted GPS device, I must have done at one time or other.

So, no, don't tell me, it's not permitted because of 'the class' they will not 'allow' a polar thing to be constructed for their craft?

Oh and does this mean it's also illegal to take an iPhone out according to some classes? Given it's GPS and various tracking apps?

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