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  #1  
Old 9th May 2013, 06:30 PM
svquintana svquintana is offline
Boat: Building KH 49, resin infused catamaran
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Default Preferred light air sails on a light cat.

Hello, I'm building a 49 foot performance cat, and would like to ask about preferences for light air sails.

The boat is a 3/4 fractional rig, with self tending jib. 75m2 Mainsail, 30m2 Jib, lightship 5000kg, max displacement 8500kg, length: 15m, Beam 7.6m.

(800sq foot Main, 325 sq foot Jib, Lightship 11000 lbs, max displacement about 18000 lbs, length: just over 49 feet, beam 25 feet)

I'm trying to spec out our sail inventory and don't know whether to choose a Symmetrical spinnaker, Assym Spinnaker, or screecher. I understand the differences between the sails, but don't know which is best suited for a fast multihull.

Finances dictate that only one of these can be purchased before launch, so I'd prefer the one that can be used the most often.

The boat is being built as a full-time cruiser, which will spend much time at sea (offshore), but not always in the trades.

I've read Chris White's book and Gregor Tarjan's book, and understand them both as to tactics, sailing "S" curves downwind, etc.

My problem is I have no direct cat experience with which to form an educated opinion.

****** My thoughts are that a Screecher or reaching symmetrical spinnaker would be my best bet. I believe they're good off the wind, and I believe they can both be used on a deep run ( say 170 degrees), even though they might not be at their best, on that point of sail.

Sail handling gear is advanced enough to make all of these sails manageable, so preference should be given to the sail with the best "all round" performance.

(Sail measurements may change slightly.)

Thanks.
Paul.

Last edited by svquintana; 9th May 2013 at 06:41 PM.
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  #2  
Old 9th May 2013, 10:08 PM
44C 44C is offline
Boat: Oram 44C cruising Australia
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Default Re: Preferred light air sails on a light cat.

Quote:
Originally Posted by svquintana View Post
I'm trying to spec out our sail inventory and don't know whether to choose a Symmetrical spinnaker, Assym Spinnaker, or screecher. I understand the differences between the sails, but don't know which is best suited for a fast multihull.

Finances dictate that only one of these can be purchased before launch, so I'd prefer the one that can be used the most often.

Thanks.
Paul.
Of the three, the assymetrical kite would probably be the best "all rounder"

Best of luck with your build!
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  #3  
Old 10th May 2013, 12:08 AM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

Thanks 44C, is that what you use?

Boat build: I can use all the luck I can get.
Thanks again.

Paul.
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  #4  
Old 10th May 2013, 12:25 AM
Woods Designs Woods Designs is offline
Boat: 28ft Skoota powercat, 18ft Strike trimaran
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Default Re: Preferred light air sails on a light cat.

As you only have a small working jib I would agree, go for the screecher as that is the only sail you can use to windward in light winds. Then a regular symmetric spinnaker as you can see underneath it and it's easy to gybe.

Only then if money permits get an asymmetric

I used my screecher a lot when crossing the Atlantic in light winds and a sloppy sea. Conditions when a spinnaker collapses all the time. You want to use self tending sails when cruising under auto pilot

Richard Woods of Woods Designs

www.sailingcatamarans.com
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  #5  
Old 10th May 2013, 02:23 AM
Peter Peter is offline
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Default Re: Preferred light air sails on a light cat.

Get a Screecher. Have it cut so that you can sheet it tight (ie up on the coach roof) not low down at the sides. You can barber haul it out to the side for downwind and broad reaching, even DDW wing on wing. For close reaching, I am assuming you don't have jib tracks, you will need a couple of pad eyes on the coach roof or one central one that you can connect a barber haul (to sheet it in). In very light winds and high boat speed you need to be able to cope with very small apparent wind angles. If you get it right and your boat is light enough you can effectively be close hauled downwind. You only need one sheet as you furl it to tack/gybe and just walk the sheet round. Get one with a torque rope (much more positive that twin line luff) and you don't need UV protection (it just adds weight to the sail) take it down when not using it. We drop and store ours in a dedicated forward locker. If you haven't already fitted a proder try to arrange it without water stays they are a pain when anchoring.

I prefer a single line furler as you can just disconnect the furling line, (the drum is empty when the sail is furled). Leave the furling line inplace but tied off down the front and you can remove the drum with the sail with no lines to tangle. With continuous furlers you have a loop of line to contend with but this is just my opinion.
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  #6  
Old 10th May 2013, 02:28 AM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

Thanks for that Richard.

The autopilot is always our primary "helmsman".

Paul.
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  #7  
Old 10th May 2013, 02:37 AM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

Thanks Peter, that all sounds like good advice. Interesting idea with the barber hauler to sheet in. I've only ever thought of a barber haul to sheet out, but using one to sheet in opens up a whole realm of possibilities.

I don't have anything on the roof, it's setup like a gunboat with solar panels on the sides and a central walkway for tending (tenting) the main. A barber haul would fit fine, for sheeting in.

Thanks for that Peter.

Paul.
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  #8  
Old 10th May 2013, 06:27 AM
44C 44C is offline
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Default Re: Preferred light air sails on a light cat.

Quote:
Originally Posted by svquintana View Post
Thanks 44C, is that what you use?

Boat build: I can use all the luck I can get.
Thanks again.

Paul.
All we have are our working sails - main and jib. Most of the time that's ample. Really, its only sailing downwind in light stuff I would like more sail area. Upwind we generate enough apparent wind, so even if it's only blowing 7-8 knots we move quite well. Around 5-7 kts boatspeed.

Reaching we get pretty close to windspeed.

I based my comment on a conversation with Phil Wise, who built and owns a very slippery 60 footer. He has a screecher, but since getting his assy spinnaker, he never uses it. Last I saw him he was planning to take the screecher off the boat.

He says he can use the assy kite from close reaching to near DDW. In light breeze downwind he can drag the AWA forward by 60-70 degrees, which is how he goes near DDW. (True)
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  #9  
Old 10th May 2013, 11:49 AM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

So many ways to skin a cat. Or sail a cat...

What size is your jib 44c? If my boat sails nearly as well as yours, I'd be a happy sailor.

Now all I need is some "sail time" on a fast cat with each of these sails. Or, I may wait until I launch the boat, borrow a sail or two and see which I prefer.

A sistership used 3 different sized spinnakers for his tradewind sailing, and sailed from Mexico to the Marshalls several times. He was in his mid 60's at that time, and mostly used his spinnakers during tradewind sailing.

I won't really know how quick my boat is until we start sailing. It may not be as quick as I had expected, which would affect apparent wind and thus sail choice. My goal is to keep sailing in very light winds, we hate to motor.

More input is always welcome, please keep the comments coming.

Thanks
Paul.
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  #10  
Old 10th May 2013, 12:37 PM
Peter Peter is offline
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Default Re: Preferred light air sails on a light cat.

Quote:
Originally Posted by 44C View Post

I based my comment on a conversation with Phil Wise, who built and owns a very slippery 60 footer. He has a screecher, but since getting his assy spinnaker, he never uses it. Last I saw him he was planning to take the screecher off the boat.

He says he can use the assy kite from close reaching to near DDW. In light breeze downwind he can drag the AWA forward by 60-70 degrees, which is how he goes near DDW. (True)
This is often the result of not being able to sheet tight enough because the sailmaker has made the leech too long or the sheeting points are too wide. I wonder where he sheets to. You should be able to pull it down to 35-40 degrees apparent, much better than an assy spin.
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  #11  
Old 10th May 2013, 02:58 PM
Woods Designs Woods Designs is offline
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Default Re: Preferred light air sails on a light cat.

Like Peter I would barberhaul in, but it does mean the cockpit is full of ropes

I much prefer a continuous furling line. Otherwise the head of the sail won't roll up properly. One other advantage over a spi - when rolled up and dropped a screecher is an easy stow sausage

Richard Woods
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  #12  
Old 10th May 2013, 04:16 PM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

I think you can now roll up the spinnaker too, there are "top down" furlers that seem to work well.

Paul.
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  #13  
Old 10th May 2013, 07:44 PM
Woods Designs Woods Designs is offline
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Default Re: Preferred light air sails on a light cat.

True, and people who have them like them.

Richard Woods
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  #14  
Old 11th May 2013, 12:07 AM
44C 44C is offline
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Default Re: Preferred light air sails on a light cat.

A spinnaker in a sock is pretty easy to stow too.

A screecher could have UV protection fitted, and usually be kept in place though, which is certainly an advantage over dragging a sail out of a locker.
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  #15  
Old 11th May 2013, 12:24 AM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

Yes, I hadn't thought of that. Our Assym had a sock, but as you said, we had to drag it in and out of storage. Having a sail up and ready probably means it'll be used more often.

I suppose a spinnaker (assym or sym) could be left up for an entire passage, just like a screecher, if you had a top down furler. Even crossing an ocean isn't going to cause that much UV damage in a month of being furled and up.

Do folks keep screechers up permanently? Or semi-permanently? Is it a sail that just stays up there all the time, except for maybe in a gale? If it's got a uv cover, folks must keep them up a long time...

I like that idea.

These are all great comments, thank you all for your ideas. This has to be the most "on topic" thread I've seen yet. I'm getting a clearer picture now of the merits of each sail.

Can anyone comment more on wind angles? I'm starting to think that a Sym spinaker would be at the bottom of my want list. It would seem to come down to an asym or a screecher. The uv thing gives the screecher an edge over the asym for ease of use.


Paul.

Last edited by svquintana; 11th May 2013 at 12:31 AM.
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  #16  
Old 11th May 2013, 12:39 AM
Woods Designs Woods Designs is offline
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Default Re: Preferred light air sails on a light cat.

Leaving it up does slow you down. You probably won't notice when cruising but you do when racing. And even if you have a UV strip it will still get dirty and maybe vibrate the mast at anchor. Its easy to take down, quicker than putting on a sail cover

I don't know how fast you boat is. On our Strike trimaran we only use a screecher as its so much easier to use than a spi. And we can pull the apparent wind way forward even at 160deg true aft wind we are almost going to windward.

And we only day sail, which means we try to reach everywhere. "Going where the wind blows" eventually means we'd have to beat back

Everyone has different ideas and everyone sails differently, so what works for one person won't work for others

So the BEST idea is to buy one of each, see how much you use them and then you'll know. That's what I did with my Eclipse. I rarely used the masthead assy, I used the screecher ocean sailing a lot (I tended to motor in light winds to windward inshore) and used the regular spi extensively inshore and off, often with no mainsail set

If you have a well cut symmetric spi you can point very nearly as close as an asymmetric one does (ie apparent wind forward of the beam at say 60deg). On a performance boat you don't let the app wind go aft of abeam

Richard Woods of Woods Designs

www.sailingcatamarans.com

Richard Woods

Last edited by Woods Designs; 11th May 2013 at 01:39 AM.
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  #17  
Old 11th May 2013, 01:10 AM
44C 44C is offline
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Default Re: Preferred light air sails on a light cat.

Quote:
Originally Posted by svquintana View Post
Yes, I hadn't thought of that. Our Assym had a sock, but as you said, we had to drag it in and out of storage. Having a sail up and ready probably means it'll be used more often.

I suppose a spinnaker (assym or sym) could be left up for an entire passage, just like a screecher, if you had a top down furler. Even crossing an ocean isn't going to cause that much UV damage in a month of being furled and up.

Do folks keep screechers up permanently? Or semi-permanently? Is it a sail that just stays up there all the time, except for maybe in a gale? If it's got a uv cover, folks must keep them up a long time...

I like that idea.

These are all great comments, thank you all for your ideas. This has to be the most "on topic" thread I've seen yet. I'm getting a clearer picture now of the merits of each sail.

Can anyone comment more on wind angles? I'm starting to think that a Sym spinaker would be at the bottom of my want list. It would seem to come down to an asym or a screecher. The uv thing gives the screecher an edge over the asym for ease of use.


Paul.
Our friends have a screecher permanently mounted on a hard foil furler. Unless a gale is forecast, it stays there all the time. It's certainly easy to use - just a bigger headsail, albeit one that has to be furled to tack.

And it works amazingly well to windward. On light days they can use it up to about 30 degrees apparent. A loose luff furler wouldn't go that high though. It's range is from about 30 degrees to about 120 apparent.

They also have a symmetrical kite, which they can fly from DDW up to near 50 degrees apparent.
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  #18  
Old 11th May 2013, 01:45 AM
Peter Peter is offline
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Default Re: Preferred light air sails on a light cat.

Quote:
Originally Posted by svquintana View Post
Yes, I hadn't thought of that. Our Assym had a sock, but as you said, we had to drag it in and out of storage. Having a sail up and ready probably means it'll be used more often.

I suppose a spinnaker (assym or sym) could be left up for an entire passage, just like a screecher, if you had a top down furler. Even crossing an ocean isn't going to cause that much UV damage in a month of being furled and up.

Do folks keep screechers up permanently? Or semi-permanently? Is it a sail that just stays up there all the time, except for maybe in a gale? If it's got a uv cover, folks must keep them up a long time...

I like that idea.

These are all great comments, thank you all for your ideas. This has to be the most "on topic" thread I've seen yet. I'm getting a clearer picture now of the merits of each sail.

Can anyone comment more on wind angles? I'm starting to think that a Sym spinaker would be at the bottom of my want list. It would seem to come down to an asym or a screecher. The uv thing gives the screecher an edge over the asym for ease of use.


Paul.
To recap.

Spinnaker - 2 guys, 2 sheets, 2 sock lines, 1 halyard
Good 180 - 100 degrees
Cannot be used to windward.
Requires 2 crew to put up take down (can be done with 1 after a lot of practice)
Requires tending, but not much DDW
Collapses in light variabe winds
Is all or nothing.
Need to go forward to douse in a squall.
Can get tangled.
Normally requires additional winches.


Asym Spin - 2 guys, 2 sheets, 2 sock lines, 1 halyard
Good 180 - 80 degrees
Cannot be used to windward.
Requires 2 crew to put up take down (can be done with 1 after a lot of practice)
Requires constant helm control and trimming.
Collapses in light variabe winds
Usually requires mainsail to blanket when dousing in any kind of blow. Need to go forward to douse in a squall (less so with furler but the resulting sausage is very sloppy and you will need to get it down.
Can get tangled.
Normally requires additional winches.

Screecher - 1 sheet, 1 furling line, 1 halyard
Good 180 - 35 degrees
Can be used to windward
Can be used in very light airs
Can be used wing on wing with the jib DDW and furled instantly during squalls but still leaving jib up during strong winds.
Requires virtually no tending especially downwind
Can be controlled from cockpit by 1 person
Can be used with or without mainsail
Can be left up during a squall
Resulting sausage is very compact.


IMO you should not have UV on a screecher it adds too much weight and bulk and reduces its performance in very very light airs. There is no reason to drop it during a squall or on a passage but as soon as you anchor it is a 2 min job to stow in a forward deck locker. All this is accomplished by 1 person. If you are beating it is worth dropping it on the tramp as it does have a windage effect and will slow you down.

Everything is a compromise and if you are racing have all three and a willing alert crew to squeeze out the last fraction of a knot, if you are cruising with one asleep and one on watch reading or doing other things is the norm in which case a screecher gives you the best overall performance for the least effort.
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  #19  
Old 11th May 2013, 02:40 AM
svquintana svquintana is offline
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Default Re: Preferred light air sails on a light cat.

Nice recap Peter, thanks.

When you put it that way, it sure looks like the Screecher is the way to go.

We've never had crew on long passages, it's always the two of us. Then of course, one of us is often sleeping, and when I think about it, I'd probably get more sleep with a screecher, since my wife could furl it on her own.

Thanks very much guys for your very helpful thoughts on this subject, it looks like all three of you consider the Screecher to be the easiest to handle. And you all seem to agree it's the most useful option for upwind sailing. I think with what I've learned here, we'll try a screecher before a spinnaker.

One final spec on the boat I didn't mention. Hull beam to length ratio is only 12. Performance cruiser range, I believe. But the rest of the numbers look quite good, so I'll cross my fingers and let you know when we launch.

Thanks very much to the three of you for your help. I'm fortunate to have had all three of you answer my questions regards light air sails. Lots of experience there. And now I know much more than I did last week.

Cheers.
Paul.
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  #20  
Old 11th May 2013, 03:43 AM
44C 44C is offline
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Default Re: Preferred light air sails on a light cat.

Quote:
Originally Posted by Peter View Post
Screecher - 1 sheet, 1 furling line, 1 halyard
Good 180 - 35 degrees
Can be used to windward
Can be used in very light airs
Can be used wing on wing with the jib DDW and furled instantly during squalls but still leaving jib up during strong winds.
Requires virtually no tending especially downwind
Can be controlled from cockpit by 1 person
Can be used with or without mainsail
Can be left up during a squall
Resulting sausage is very compact.

I agree with all this except the good at 180 degree part. They may just work at 180 degrees, but they don't work well.

The downside is the cost. There's the prodder, the prodder guys, and the furler to buy before you even get to the sail.
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