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plenamar

Jib (on furler) area rule-of-thumb

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Appreciate opinions (I do not have access to sail plan or NA)

 

125 % Genoa on 36 ft steel cruising boat has aprox 37 mt^2 sail area. Ketch with cutter stay.

We are planning on buying a jib to put on Genoa stay (back-up sail to be used mostly in Patagonia)

What size (expressed as a % or current 125 % genoa) would  be "reasonable" for a jib? It is set on a furler. The current Genoa is practically new, jib would be used offshore.

Thanks

 

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A 130 is the recommendation I seem to see for the most part for a cruising furler.

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1 hour ago, SloopJonB said:

A 130 is the recommendation I seem to see for the most part for a cruising furler.

He already has a 125.

I like a blade on a furler, reinforced for a reef 3 or 4 rolls in. After I get too weak to crank my 130 in I'll get a 105. Just enough overlap to be annoying.

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Have a 142 and a 108. Use the 108 almost exclusively.  A lot depends on track locations. Also, for a dedicated offshore sail, clew height is important.  Talk through use case with your sailmaker

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Given what you have and your plans to sail in the lower lats I’d be inclined to go  90-100% and get get a relatively high clew height, one for visibility, two water  on the lower third of sail and three relative ease of handling. I’d go with something like a tri-radial to give you durability especially given the wind ranges Down that way.

Thats my 10 cents worth.

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Yes, about 105%. Maximum that will fit foretriangle without hitting spreaders.

Make sure you get extended tack reinforcements for the foot and reef position markings on both sides of the sail so you can see them at night with a flashlight.

 

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10 hours ago, Zonker said:

Yes, about 105%. Maximum that will fit foretriangle without hitting spreaders.

Make sure you get extended tack reinforcements for the foot and reef position markings on both sides of the sail so you can see them at night with a flashlight.

 

Thanks, good advice

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Assuming that the deck layout is OK for this, I would consider a self-tacker. IMHO, it is priceless when close to the coast or in a busy area. Jib would have to be more like 95% but it shouldn't make such a big difference. It also means that in shifty conditions upwind you will be more likely to tack with shifts and this saves you lot of distance!

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As a general rule, the more you roll the sail the worse it works, so going smaller and needing to furl less is generally a win. I like the idea of a small-ish furling jib and an asym for light air off-the-wind. A generic suggestion would be in the 130-120 range.

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