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Old 16-05-2011, 07:56   #1
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Greater Angles when Reefed

Under full sail at perhaps 10 to 15 kts true wind - close hauled it looks like 40 deg (AWA) is as close as she likes to go and stay in the groove.
As the wind gets up my min effective AWA seems to go up. For example, by 20kts true, closest seems to be about 50 deg AWA.
I'm picking this is due to the less efficient shape of the Genoa as you furl.
Any contrary or more informed views?
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Old 16-05-2011, 08:14   #2
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Re: Greater angles when reefed..

A tall aspect rig will out point a short aspect rig. When you reef, you change the rig to low aspect.
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Old 16-05-2011, 08:16   #3
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Re: Greater angles when reefed..

Excuse my ignorance , but what do you mean by AWA?
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Old 16-05-2011, 08:17   #4
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Re: Greater angles when reefed..

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Any contrary or more informed views?
Depending on the sails you may be able to do better. A medium sized head sail would hold it's shape better in high winds than a larger sail.
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Old 16-05-2011, 08:31   #5
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Re: Greater angles when reefed..

G'Day FN,

When reefing the genoa, do you move the sheet lead cars forward to maintain the proper twist in the sail? If not, this could be your answer.

If you do move them correctly, then your thoughts about loss of shape when reefed are likely correct. Also, does your sail have a luff pad to help flatten it when reefed? If not, then it is even more likely that shape changes when reefed are your problem. If the sail is new enough to warrant spending some money on it, luff pads can be retrofit by your friendly sailmaker.

Good luck
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Old 16-05-2011, 08:33   #6
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Re: Greater angles when reefed..

Alecadi

Apparent Wind Angle
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Old 16-05-2011, 10:44   #7
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Re: Greater angles when reefed..

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Alecadi

Apparent Wind Angle
OH YES tks
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Old 20-05-2011, 06:03   #8
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Re: Greater Angles when Reefed

FraidNot, good advice from all above. A question: you mention reefing your genoa, but have you also reefed your mainsail? I generally find that you will keep better balance and performance upwind by reefing your mainsail first.

Brad
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Old 20-05-2011, 06:12   #9
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pirate Re: Greater angles when reefed..

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Alecadi

Apparent Wind Angle
Dang.... I thought it was Always Wants Alcohol..... seeing as after anchors and guns.... Rhum is the most quoted thing on CF....
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Old 20-05-2011, 06:38   #10
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Re: Greater angles when reefed..

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Dang.... I thought it was Always Wants Alcohol..... seeing as after anchors and guns.... Rhum is the most quoted thing on CF....
Always Wants Ammo or Always Wants Anchors

Juniper does the same when I roll in the sails, both on vertical furlers.
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Old 20-05-2011, 07:10   #11
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Re: Greater Angles when Reefed

Hi all: Remember sea state changes with increases in wind speed ;driving a boat into larger seas will require the boat to be sailed more fully even if your sails set as well when reefed. More modern designs with very full sections forward (to increase interior volume) will be harder to drive into larger waves than many older designs with finer entries , all else being equal. Something to think about while looking at boats on the showroom floor. I know some naval architects may be lurking here and hopefully enlighten us further regarding all this. Thanks
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Old 20-05-2011, 08:05   #12
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Re: Greater Angles when Reefed

Pointing angle is all about L/D i.e. lift vs Drag.

A tall thin wing has better lift characteristics (L/D) than a small fat wing. Your windage (other than sails) is fixed and adds to drag, so as you reef, your L/D goes down and with it your pointing ability.

John Shuttleworth has the maths on his site if you fancy it....

Multihull Design Considerations for Seaworthiness
In the section titled: Windward ability
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Old 20-05-2011, 08:36   #13
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Re: Greater Angles when Reefed

The reason for the luff pads suggested by Cate, is that as you roll up the sail the draft moves forward and gets deeper. The luff pads reduce that problem. The wind has to come approximately from where the leading edge of the sail points. A flatter sail allows the wind to come from more nearly in front of the boat without the wind hitting the leeward side of the sail causing it to luff, a rounder entried sail the wind has to come more from the beam.


Anybody else have a problem with a 40 deg AWA on an Oceanis, that sounds big to me.

John
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Old 20-05-2011, 09:01   #14
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Re: Greater Angles when Reefed

It seems like a sail trim problem--not finding ways to flatten the sails in higher winds. This can happen because the sails are stretched, or because the appropriate controls are not being used. If you're running a big genny, it's almost inevitable.

Changing to a smaller foresail is magic. I have an 85% jib that I often use in the summer months, and it allows me to point every bit as high as the 110% jib I use primarily for winter sailing. Our average summer day blows 25 knots here in SF bay, and I can go plenty fast with the summer sail.
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Old 20-05-2011, 09:48   #15
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Re: Greater Angles when Reefed

Roller-reefing a headsail is completely incompatible with pointing. Even with luff pads. Any modern boat with good sails should trim to around 30 degrees AWA or better. Your 40 degrees indicates something is wrong. But good sails are generally not found on cruiser's boats. Changing to a smaller headsail and reefing the main shouldn't change the AWA much. But the higher winds and seas will probably increase the leeway (course).

I have my genoa either all the way out or fully furled. Beating with just the main is not any worse than sailing with a roller-reefed genoa.
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