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PostPosted: Sat Aug 17, 2013 6:50 pm 
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I have read of people hollowing the end of their paddle to push the sail out on downwind runs, but I have changed it a little bit.

At each end of my paddle, I have cut out a little 1/4 inch square right on the end. This is small enough to catch one of the knots in the cord attached to the clew of the sail, and lock it in quite reliably.

On a downwind run, I now catch the clew in the paddle, push the paddle out and release all the mainsheet. This puts the clew the whole paddle length out to one side, maximising the surface area facing the wind, while creating a triangulated clew which doesn't move around.

The speed increase is instant and persistant, not a bad return for losing a 1/4 inch square from the paddle, without the need to complicate things with barber-haulers.

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PostPosted: Sun Aug 18, 2013 2:18 am 
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I did the calculations Tony of what a stiffened sail area is compared to an unstiffened. The calc. is back in the forum threads somewhere, can't remember what it was but it was quite substantial. But as you can see the speed increase is huge. Although I use the flexiboom, the results are pretty similar I'd imagine. It would have to be the simplest and cheapest mod you could possibly do to gain more speed.

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PostPosted: Sun Aug 18, 2013 9:58 am 
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Location: Southwest Calif.
I've also done that mod to my paddle. It works great !
It's all about getting a full utilization of whatever gear you have aboard to maximize efficientcy.
I also use that paddle to swat big bugs. :D

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PostPosted: Sun Aug 18, 2013 5:38 pm 
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And I have seen video of a paddle being used to push a shark away, repeatedly....

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PostPosted: Mon Aug 19, 2013 6:44 pm 
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Can you please post a pic of how you use the paddle for downwind. I get that you are cupping the sail.


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PostPosted: Mon Aug 19, 2013 6:53 pm 
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Until I can get a photo, I will try and explain it better. The paddle doesn't touch the sail at all. The little string dangling from the clew (used to wrap around the sail when it is furled, for transport etc) has several knots in it. By sliding the string through the notch in the end of the paddle, the string gets caught by the knot, effecively locking the paddle to the string. You then simply push the paddle out, while releasing the mainsheet. I find that I can release ALL of the mainsheet, but you can cleat it any time.

As you do this, the clew of the sail will move out to past the ama, and forward, until you have close to the maximum sail area visible from behind you where the wind is coming from (although the setup will work just as well with the wind as much as 45 degrees forward from dead astern).

The inner edges of the paddle can then be either held against your hip, or put into the mesh pocket on that side (I don't do that). In my case, due to my elevated skipper seat, I put the inner end of the paddle under the seat, against the swivel.

I'll get a photo next time out.

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PostPosted: Tue Aug 20, 2013 1:33 pm 
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What an awesome idea! All this time I've just poked along down wind. For those of us with the original seat. Perhaps a notch on both ends of the paddle and a knob, button, or another knotted piece of rope mounted to the deck to secure the other end. Time to experiment!


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PostPosted: Tue Aug 20, 2013 2:38 pm 
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Just my 2 cents: Catamarans, and I assume tri's, are faster downwind when sailed at 120 degrees off the wind, even tho you have to gybe. Straight downwind is not the fastest from point A to point B. The Hobie 14 catamaran (main only) is usually sailed straight downwind, an exception. Besides, running on a broad reach is way more fun.


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PostPosted: Tue Aug 20, 2013 4:42 pm 
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Your comments are quite true for vessels with planing hulls; however, Islands do not fit in that category, so apart from the odd temporary surf, we can normally expect a limited top speed downwind. Holding out the maximum sasil area increases the speed available within those limits, unless we have so much wind that maximum speed can be maintained even with a partly furled sail (I have sat on 7 knots in flat water with half the sail furled, and the bow of my TI under water back to the mast, as I expect most of us have done).

By holding out the sail, you can go faster closer to directly downwind, and still have the fun you mentioned from gibing at an angle.

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PostPosted: Tue Aug 20, 2013 5:00 pm 
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You are probably right. I think the 120 degree works with racing cats- H16, H17, Nacra, etc; more than H14, waves, etc. I bought a TI this spring--it is a fun boat, very versatile.


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PostPosted: Tue Aug 20, 2013 5:25 pm 
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I don't know about anyone else but I have had that dangling cord foul the pulley and jam my sail control line several times now, so I typically tie that line off. I think I will still do the paddle mod, and just take my risks with the line jamming.
Great idea.


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PostPosted: Tue Aug 20, 2013 5:40 pm 
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I was amazed at how much extra wind you can grab Tony. In this video I was trying to show, as best I could, the speed difference and the increased fun factor. I'm sure your paddle design would do virtually the same.

https://www.youtube.com/watch?v=LO9I-tR3I1E

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PostPosted: Wed Aug 21, 2013 2:40 am 
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I often prefer "tacking" downwind, but the Islands. being boomless, are not as fast as some other boats on a broad reach. The thing is, the camber of the sail, and hence the drag, increase as you sheet out. The Islands' sail shape is at its most efficient when sailing close hauled.

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PostPosted: Wed Aug 21, 2013 5:07 am 
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Chris, that is the advantage of stretching out the sail using Slaughter's or my method. You can remove that hugely deep hollow in the sail. I haven't done much testing on a beam reach, but I expect it should be possible to get telltales on both sides of the sail streaming signifying efficient airflow and drive.

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PostPosted: Wed Aug 21, 2013 6:11 am 
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Tony, I carry an extendible boathook and use it the way you use the paddle. I've found it useful for sailing downwind, as you say, but more difficult to flatten the sail satisfactorily on a broad reach, in any decent wind. Slaughter's flexiboom might do the job if it is rigid enough. I could well be wrong, but I think it would be possible to have laminar airflow, as evidenced by the telltales streaming, but still have a suboptimal lift to drag ratio, due to excessive camber in the sail. It's easy to get both telltales streaming on a broad reach, even when not attempting to flatten the sail.

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