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  #1  
Old 08-10-2010
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Best angle to windward?

Enjoying my first season club racing my '82 Hunter 30 (Cherubini design sloop, 5'3" draft with 135 RF genoa, no genoa tracks just blocks snap shackled to the toe rail - but adjustable) and was wondering...

what's the fastest way to sail her to the windward mark?

Do I sheet it all in as tight and close as possible - or - ease her off a few degrees to a close close reach to keep the boat speed up?

I don't have the electronics or a slide rule to do any precise measurements or calculations - just curious if there's some fact based gouge from those sailing this same or similar boat...

Close hauled and in the groove or eased off a few degrees, what's best for a 28 year old H30?

Thanks
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  #2  
Old 08-11-2010
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Quote:
Originally Posted by malyea View Post
Enjoying my first season club racing my '82 Hunter 30 (Cherubini design sloop, 5'3" draft with 135 RF genoa, no genoa tracks just blocks snap shackled to the toe rail - but adjustable) and was wondering...

what's the fastest way to sail her to the windward mark?

Do I sheet it all in as tight and close as possible - or - ease her off a few degrees to a close close reach to keep the boat speed up?

I don't have the electronics or a slide rule to do any precise measurements or calculations - just curious if there's some fact based gouge from those sailing this same or similar boat...

Close hauled and in the groove or eased off a few degrees, what's best for a 28 year old H30?

Thanks
That really depends on a lot more than just the type of boat...

The way you trim and tune your rig, the sail plan you have up, the condition of the water plane (in a chop you need more power so you shouldn't point too high), the wind speed...

Anyway, you really don't need a bunch of electronics to determine the optimum conditions by yourself, the cheapest of handheld GPS units will provide you with all the data you need...
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Old 08-11-2010
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Quote:
Originally Posted by malyea View Post
Enjoying my first season club racing my '82 Hunter 30 (Cherubini design sloop, 5'3" draft with 135 RF genoa, no genoa tracks just blocks snap shackled to the toe rail - but adjustable) and was wondering...

what's the fastest way to sail her to the windward mark?

Do I sheet it all in as tight and close as possible - or - ease her off a few degrees to a close close reach to keep the boat speed up?

I don't have the electronics or a slide rule to do any precise measurements or calculations - just curious if there's some fact based gouge from those sailing this same or similar boat...

Close hauled and in the groove or eased off a few degrees, what's best for a 28 year old H30?

Thanks
If your genoa's on the rail yeah, bring it in tight - trim the main to match. To really go to weather well, you're gonna need inboard tracks... which would indeed allow you to be in too tight in lumpy stuff but I don't see that happening with a headsail trimmed to the rail
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Old 12-05-2010
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My very limited understanding is that you need a GPS with a VMG function. You should also get a polar VMG chart for your boat. I have read that it is very often the case that sailing slightly off your highest pointing angle when going upwind will give you a higher VMG.
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Old 12-05-2010
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Do a little Google searching on how to calculate VMG - there are lots of articles out there. From what I've read, it's quite often actually a little faster to sail slightly off of the most closely hauled point you can pinch out of the boat. But the articles will show you how to calculate your VMG with more certainty and choose your line.
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Old 12-06-2010
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Multiply the yacht's boat speed over the ground by the cosine of the angel between the bearing to the mark and the course over the ground. Eg, if the yacht is sailing a 5 knots, the bearing to the mark is 10º and the yacht's course over the ground is 40º the angle between the bearing/course is 30º, the cosine of 30º is .866 and the VMG is 4.33 knts.

FWIW...
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Old 12-06-2010
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Years ago, before I had instuments that calculate VMG, I made the simple table below. The way this was used is that I kept an eye on the knotmeter and the course for a few minutes and then made a small course change, adjusted sails and watched the change in speed, then compared it to my chart to see whether my VMG increased or decreased based on the new speed (in the field of the chart). The reason that the chart went to 40 degrees of course change was that I also used it on a run.

While a GPS has a VMG function, it is useless for this process since it is a GPS generated VMG to a fixed point, and not to a wind direction. These days, most of the better instrument systems include some form of integrated functionality, and if you have such a system, and if it includes a knotmeter and wind instrument, you should be able to get it to show VMG relative to the wind. It should be noted that your system needs to be accurately calibrated to get meaningful absolute results, but it will provide meaningful relative information.



VMG OFFSET TABLES
OFFSET ANGLE
O510152025303540
1/cos=1.00381981.01542661.03527621.06417781.10337791.15470051.22077461.3054073
0.20.200.200.210.210.220.230.240.26
0.40.400.410.410.430.440.460.490.52
0.60.600.610.620.640.660.690.730.78
0.80.800.810.830.850.880.920.981.04
11.001.021.041.061.101.151.221.31
I1.21.201.221.241.281.321.391.461.57
N1.41.411.421.451.491.541.621.711.83
I1.61.611.621.661.701.771.851.952.09
T2.12.112.132.172.232.322.422.562.74
I2.62.612.642.692.772.873.003.173.39
A3.13.113.153.213.303.423.583.784.05
L3.63.613.663.733.833.974.164.394.70
4.14.124.164.244.364.524.735.015.35
S4.64.624.674.764.905.085.315.626.00
P5.15.125.185.285.435.635.896.236.66
E5.65.625.695.805.966.186.476.847.31
E6.16.126.196.326.496.737.047.457.96
D6.66.636.706.837.027.287.628.068.62
7.17.137.217.357.567.838.208.679.27
7.67.637.727.878.098.398.789.289.92
8.18.138.228.398.628.949.359.8910.57
8.68.638.738.909.159.499.9310.5011.23
9.19.139.249.429.6810.0410.5111.1111.88
9.69.649.759.9410.2210.5911.0911.7212.53
10.110.1410.2610.4610.7511.1411.6612.3313.18
10.610.6410.7610.9711.2811.7012.2412.9413.84
11.111.1411.2711.4911.8112.2512.8213.5514.49
11.611.6411.7812.0112.3412.8013.3914.1615.14
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Last edited by Jeff_H; 12-07-2010 at 04:42 PM.
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Old 12-06-2010
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Quote:
Originally Posted by malyea View Post
Enjoying my first season club racing my '82 Hunter 30 (Cherubini design sloop, 5'3" draft with 135 RF genoa, no genoa tracks just blocks snap shackled to the toe rail - but adjustable) and was wondering...

what's the fastest way to sail her to the windward mark?

Do I sheet it all in as tight and close as possible - or - ease her off a few degrees to a close close reach to keep the boat speed up?

I don't have the electronics or a slide rule to do any precise measurements or calculations - just curious if there's some fact based gouge from those sailing this same or similar boat...

Close hauled and in the groove or eased off a few degrees, what's best for a 28 year old H30?

Thanks
First issue is to be sure that your rig is properly tuned/tensioned .... so that the forestay is stretching to its proper 'sag to leeward curve' and that sag 'matches' the 'hollow' shape that the sailmaker designed/cut into the luff of the genoa. Without proper rig tune and without proper backstay tension (which by reaction tensions the forestay) the 'usual' is that with a too loose forestay the genoa will be 'draft aft', too full and with its leech 'hooking up to weather' .... the boat will aggressively heel over, will be slow and will tend to skid off to leeward and with the helm pressure will be high (and the helmsman erroneously thinking 'weather helm'). You can also be at less than optimum with a too tight forestay.
Pulling in on the jib sheets too tightly can easily 'force' an increased 'sag' in the luff of a genoa; so, if you need to pull the jib sheets in tight you also have to tighten the backstay to keep the forestay and the luff of the genoa at is 'designed' shape. Ignoring the above, if you set your backstay at 15-18% tension in 15kts. of wind strength, you will be 'close' to the correct forestay sag when beating with 'moderate' jib sheet tension.
Summary - if the forestay (backstay) tension isnt correct, all the sail trimming in the world, etc., etc., etc., isnt going result in a boat that is 'fast' nor 'points well'. If you want optimum or 'precision', I can 'detail' this further/later if you desire, lemme know.

Second, is to use a FULL set to telltales at the luff, at the leech. and also to have a row of 'steering tell tales' about 6-8' off the deck on the genoa to help you visually and precisely keep the boat in the 'groove'. The 'benchmark' seminal article for the use of tell tales is found @ ArvelGentry.com ---->magazine articles ----> then a series of 4 articles beginning with "Checking trim while on the wind". A 'simplified' version of these four articles can be found at: Telling tales ...

A good basic article for 'performance sailing upwind' including sail trim, boat handling and helmsmanship: Performance Racing Tactics .... Id advise this article after you master the 2 issues above.

Third, All the above is accomplished by practice/practice/practice to quickly evolve your skills .... THEN when you master the above, you can start to consider the important VMG function to optimize all the above and to be 'sailing at the proper/precise angles' and in the 'right' direction, etc.

Then, after the above are 'mastered' so your are going the fastest possible and in the 'right direction', then you can further concentrate on racing 'tactics' so that your boat is positioned at the correct location/position the course to take best advantage of wind shifts, errors of other boats, etc. etc. etc. etc. A good basic text for this would be: "Sailing Smart" by Buddy Melges and Charles Mason (probably out of print).

Also, if your main has the 'usual' boltrope at the luff, I can offer (later) some 'tricks' that will allow an almost perfect 'set' or shape to affect better pointing, etc. If your main is made from 'woven dacron' then this becomes quite important.

Without correctly setting up a boat and without proper sail shaping, following a VMG plot is somewhat pointless .... until your ARE fast and ARE pointing at the optimum angles, etc.

hope this helps. ;-)

Last edited by RichH; 12-06-2010 at 11:47 AM.
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Old 12-07-2010
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Quote:
Originally Posted by malyea View Post
...

what's the fastest way to sail her to the windward mark?
This question has many different answers depending
the conditions you are sailing in. Given that you are
using a furling sail sheeted to the rail, you will
necessarily be footing somewhat. You will always
want to build up your boat speed before attempting
to point high. With a 135% Genoa your optimal wind
range is likely to be 12-15 knots TWS, with this wind
and flat water you should be able to sheet the sail in
to the spreader and point relatively high. In lighter winds
or choppy water you will need to trim out a bit and foot
off to maintain boat speed. Your ultimate guide will be
the boats you are sailing 'against', select the boat
that is most similar to yours and use them as a
benchmark.
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Old 12-07-2010
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Quote:
Originally Posted by RichH View Post
First issue is to be sure that your rig is properly tuned/tensioned ...
( ... SNIP ... )
.... THEN when you master the above, you can start to consider ...
( ... SNIP ... )
...Then, after the above are 'mastered' so your are going the fastest possible and in the 'right direction', then you can further concentrate on ...
( ... SNIP ...)
OM flippin G.

I am constantly amazed at the amount of knowledge on this forum. The idea that Rich can just rattle that off the top of his head (like, DUH, it's all obvious, right?) with more on tap should you be interested totally makes my cold snowy Toronto winter day.

Not sure what all the apostrophe-quotes are for but I assume they make Rich's boat go faster
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