| Re: Tacking angle
[Re: pgp]
#246152 03/26/12 02:20 PM 03/26/12 02:20 PM |
Joined: Jan 2009 Posts: 5,525 pgp OP
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Posts: 5,525 | I'll bet those two know right down to the minute!
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Tacking angle
[Re: pgp]
#246164 03/26/12 02:53 PM 03/26/12 02:53 PM |
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Posts: 5,525 | Thanks! Much appreciated.
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Tacking angle
[Re: pgp]
#246168 03/26/12 03:28 PM 03/26/12 03:28 PM |
Joined: Dec 2001 Posts: 5,590 Naples, FL waterbug_wpb
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Posts: 5,590 Naples, FL | Slight variation in subject: can you sail your A cat at 70 degrees(without pinching)? I would have guessed 45-50 degrees would be ideal upwind, and 125-160 down? But that's a sloop/spin boat with a decent breeze and flat water.. It's all in the telltales...
Last edited by waterbug_wpb; 03/26/12 03:28 PM.
Jay
| | | Re: Tacking angle
[Re: pgp]
#246171 03/26/12 03:34 PM 03/26/12 03:34 PM |
Joined: Jan 2005 Posts: 6,049 Sebring, Florida. Timbo
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Posts: 6,049 Sebring, Florida. | Racing cats isn't the 'rocket science' that racing slow boats is.
Just go as fast as you can, as long as you can, then tack! (or gybe)
In Rick's excellent book, Catamaran Racing for the 90's, Randy Smyth wrote, "Speed isn't everything, it's the only thing!"
I'd much rather overstand A mark a bit and come in hot, than undershoot it a little and pinch all the way up to it, or worse yet, have to do two more tacks if I come up short.
But on a 24-30 foot monohull, you're only going 5-8 knots upwind (depending on your boat type) and if you've overstood, cracking off 10 degrees isn't going to give you the huge speed increase that it does on a cat. So, yeah, they care about tacking angles and need to get it right, a lot more than we do.
Blade F16 #777
| | | Re: Tacking angle
[Re: pgp]
#246174 03/26/12 03:46 PM 03/26/12 03:46 PM |
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Posts: 5,525 | My first goal is to open communications with someone half my age. She asked a question, I'm going to find an answer.
The tacking angle is really just the edge of the bigger picture. I do pretty well just looking over my shoulder to determine when to tack. On the other hand detecting shifts and currents and allowing for each requires a little more finesse (that I don't really have). Maybe she does. But, one step at a time...
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Tacking angle
[Re: pgp]
#246178 03/26/12 04:01 PM 03/26/12 04:01 PM |
Joined: Nov 2005 Posts: 1,203 uk TEAMVMG
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Posts: 1,203 uk | Because you won't know where your frickin' boat will be pointing after you tack!!!!!!!!!!!!
Too many hippies in here "Just shut your eyes and let the boat flow maaaaaaan!"
Paul
teamvmg.weebly.com
| | | Re: Tacking angle
[Re: waterbug_wpb]
#246179 03/26/12 04:05 PM 03/26/12 04:05 PM |
Joined: Aug 2003 Posts: 351 Santiago, Chile Andinista
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Posts: 351 Santiago, Chile | Slight variation in subject: can you sail your A cat at 70 degrees(without pinching)? I would have guessed 45-50 degrees would be ideal upwind, and 125-160 down? But that's a sloop/spin boat with a decent breeze and flat water.. It's all in the telltales... I think we mean the angle between one tack and the next, not the agle between irons and current direction. Translating your numbers it would be 90-100 for tacking and 40-110 for gybing. (right?) I think it's not about the telltales. You follow the telltales, true, but first you choose how high you want to go and set the sails for that, I think that's what we are talking about. For the few measurements with iRegatta I've done, it seems that VMG (towards wind direction) changes little if I open the tacking angle a bit (say up to 10 degrees). Speed increase almost equals the effect of lower angle. And beyond that yo may go faster (though not a lot more) but slower towards wind direction. As said before, it changes with wind speed and conditions. It's cool to measure it, if you don't get crazy about it anyway.. Just set the wind direction and speed and forget about it, let the software capture the data. You can watch your speed every once in a while too and that's it. Then you download the readings and have fun again in front of your computer (in the office maybe..)
Last edited by Andinista; 03/26/12 04:07 PM.
| | | Re: Tacking angle
[Re: pgp]
#246189 03/26/12 04:52 PM 03/26/12 04:52 PM |
Joined: Aug 2007 Posts: 3,969 brucat
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Posts: 3,969 | Not about the telltales? I won the New England 100 one year, following nothing but the telltales (of course, that was primarily a reaching race, on a year that the wind angle made it tough to fly a spinnaker).
Of course, that's on a Hobie 16, the jib telltales are everything (Doug Baker taught me this). Upwind, I rarely look at the Windex, unless it's blowing over 15 knots; at which point, I can't get the windward jib telltale to fly unless I pinch to the point that we nearly stop. In light to moderate breeze, I just sheet in and steer to the jib telltales. I can actually point higher this way in lighter, flatter water than I ever could just by watching the Windex.
Mike | | | Re: Tacking angle
[Re: pgp]
#246215 03/27/12 06:34 AM 03/27/12 06:34 AM |
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Posts: 5,525 | I've been using a Garmin Foretrex, but it is such a pita to upload!
For that and other reasons I've ordered a Speed puck.
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Tacking angle
[Re: pgp]
#246277 03/27/12 02:19 PM 03/27/12 02:19 PM |
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Posts: 5,525 | None of them show tacking angles less than 90degrees so I'm a little skeptical of those claims to contrary.
Anyone have an explanation?
Last edited by pgp; 03/27/12 02:19 PM.
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Tacking angle
[Re: pgp]
#246278 03/27/12 02:32 PM 03/27/12 02:32 PM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | the faster you go, the sharper the angle of your apparent wind becomes. You can point higher, but you go slower.
Jake Kohl | | | Re: Tacking angle
[Re: pgp]
#246279 03/27/12 02:46 PM 03/27/12 02:46 PM |
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Posts: 5,525 | Yes, but I'm not seeing where that will yield tacking angles of 70 or 80 degrees unless it's a measure of apparent wind.
The tacking angles cited above are for true wind not apparent.
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Tacking angle
[Re: Andinista]
#246283 03/27/12 03:15 PM 03/27/12 03:15 PM |
Joined: Aug 2007 Posts: 3,969 brucat
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Posts: 3,969 | From the hobie pdf page 7 above, the best tacking and gybing angles for that polar would be 100° and 100°. (points at 50° and 130° on the plot). Those polars show straight-line speed, not VMG. Depending on the conditions, it may very well be better to sail higher/deeper to get around the course faster. On a Hobie 16, I have seen that when the wind shuts down, and the race isn't abandoned, the best course downwind is as straight to the mark as you can go without gybing. Mike | | | Re: Tacking angle
[Re: brucat]
#246287 03/27/12 03:31 PM 03/27/12 03:31 PM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | From the hobie pdf page 7 above, the best tacking and gybing angles for that polar would be 100° and 100°. (points at 50° and 130° on the plot). Those polars show straight-line speed, not VMG. Depending on the conditions, it may very well be better to sail higher/deeper to get around the course faster. On a Hobie 16, I have seen that when the wind shuts down, and the race isn't abandoned, the best course downwind is as straight to the mark as you can go without gybing. Mike And they're also only for 10 knots (I think it was 10) of boat speed. As the wind speed changes, the polars change for each boat.
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