Rossiter Pintail Mortagne sur Gironde, near Bordeaux |
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Laser 28 - Excellent example of this great design Hamble le rice |
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Training aid idea |
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Sam.Spoons ![]() Really should get out more ![]() Joined: 07 Mar 12 Location: Manchester UK Online Status: Offline Posts: 3400 |
![]() ![]() ![]() ![]() Posted: 27 Aug 20 at 1:11pm |
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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish" |
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Mozzy ![]() Far too distracted from work ![]() Joined: 21 Apr 20 Online Status: Offline Posts: 209 |
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I'd set it about 50km away. It's only a waypoint. The further away it is, the less susceptible it is to wind shifts and skew as you sail out to one side.
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Mozzy ![]() Far too distracted from work ![]() Joined: 21 Apr 20 Online Status: Offline Posts: 209 |
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What would be easier (albeit rough), is to consider what sort of speed increase you need to make a 5 degree foot worth it.
Do 5 tacks recording the tacking angle on your compass. Try not to tack on shifts when doing this. Look at your GPS post sailing to get an idea of your average 'steady state' upwind speed. Run the maths to ascertain how much faster you need to go when you foot 5 degrees to make it a better VMG. Then play around on the water watching your speed as you foot and pinch to see if you can achieve the required speed increase. I think that would be the only realistic way to approach the problem with the tools you have. Of course gusts and shifts wreck all this, even for instantaneous readings. And tide makes these GPS speeds meaningless. I guess this is why, despite advancements in technology, a tuning partner to see relatives against is very valuable.
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Sam.Spoons ![]() Really should get out more ![]() Joined: 07 Mar 12 Location: Manchester UK Online Status: Offline Posts: 3400 |
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Thanks Mozzy, I did try it yesterday and was not able to get it to work satisfactorily. I just want to get a feel for the differences between pointing and footing really so a waypoint a couple of miles upwind would keep me in the middle of the window for a few hundred metres. The Garmin I'm using updates once per second.
Edited by Sam.Spoons - 27 Aug 20 at 10:34am |
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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish" |
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Mozzy ![]() Far too distracted from work ![]() Joined: 21 Apr 20 Online Status: Offline Posts: 209 |
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VMG toward a mark or waypoint is pretty useless for upwind tuning. The long tack will always show as better VMG. The nearer you get to the layline, the worse your VMG reading will be.
You need velocity in the direction of the true wind over water (i.e. how fast are you doing upwind). Whether you want to follow the number real time or do post sailing analysis then the data needs to be pretty high resolution (1 sec interval or less) and you'll need to adapt your target numbers for wind speed too. This is something most racing yachts will have and be doing if they are good. But I don't think it's possible to recreate it on a dinghy with only a GPS.
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Sam.Spoons ![]() Really should get out more ![]() Joined: 07 Mar 12 Location: Manchester UK Online Status: Offline Posts: 3400 |
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Zombie thread revival alert.....
Just been thinking more about this. I think I'm struggling to make best VMG upwind so I've decided to use my old Garmin Etrex to help out when practicing. Question, for the VMG feature to work a waypoint some distance upwind is required. I'm just trying to get a feel for the best compromise between pointing high and footing fast so, as I see it, it doesn't really matter exactly where that is for my purposes as long as it's in the 'no-go' window?
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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish" |
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tink ![]() Really should get out more ![]() Joined: 23 Jan 16 Location: North Hants Online Status: Offline Posts: 789 |
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The changing frequency was the the thought of thing I figured would work I am dyslexic which means I don’t make the normal connections and has helped my career as a design engineer. Any ho - from bike speedo - bike bell, impeller rotates the hammer of a bike bell, as speed changes frequency of ‘clangs’ changes
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Tink
https://tinkboats.com http://proasail.blogspot.com |
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Sam.Spoons ![]() Really should get out more ![]() Joined: 07 Mar 12 Location: Manchester UK Online Status: Offline Posts: 3400 |
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TBF this would only be for training as most classes ban electronic aids while racing so the only others around would be your crew and/or training partner and, for both, the info would be relevant.
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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish" |
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423zero ![]() Really should get out more ![]() Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3420 |
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Audible would be a no no, people moan about my sailing watch beeping for every minute
![]() got moisture in the glass, left it in the window till it disappeared, works perfectly except for the beeping for every minute, won't go even when you cancel it in settings
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Robert
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Sam.Spoons ![]() Really should get out more ![]() Joined: 07 Mar 12 Location: Manchester UK Online Status: Offline Posts: 3400 |
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Just thinking about that one, maybe beeps would be less irritating
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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish" |
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