sail dimensions, Bene First 345 - SailNet Community
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sail dimensions, Bene First 345

Just wondering if anyone has the SA of a 100% jib for the Beneteau 345. I am attempting to right-size a storm jib (70%) and seek independent (ie noncommercial) thoughts on the right size.

I want to balance it with reef 2 on the main so the ratio of sail areas of main to jib are the same as under full sail.

Thanks,

Maxwell
maxcontax is offline

Old 10-19-2006
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Although the math is simple, there are a number of sail calculators available on the internet. One is http://www.sailingusa.info/parts_of_the_boat.htm - putting in the I (44') and J (12.9') for a standard rig 345 gives a S/A of 284.

What does right-sizing the storm jib mean? Is your storm jib really 70% - I guess I don't know what % a storm jib "should be" but ours is by eyeball maybe half or less of the area of our 85% jib.

As to matching the main, assuming you have somewhat standard reef sizes, you'd need a third reef for use with a storm jib. Do you have an inner forestay for flying the storm sail?

You might want to seek out more commercial advice....
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by the numbers

Thanks for your reply, I did the IPEJ numbers and came close to manufacturer's 540 ft2 ( it was 513 ft2) for total sail area.

Presuming a "square function" for pressure on sails, ie 70% sail area results in 1/2 the force (.7 x .7 = .49), the jib I am looking for would be 160 ft2. Maybe the problem is nomenclature: maybe it is not a storm jib, but a working jib.

When I furl the headsail to 70% and double reef the main,the boat pulls well on a reach but does not point nearly as well. My 150 has the foam pad insert to keep sail shape but the 100 does not. In 18 knots with all the laundry out it is lively and fast and points very high, but is right on the edge. for making time in good wind I am looking for a jib SA that I can hank on, furl it it gets wild, but mainly run it full size, and balanced. There are a few passages I make with pretty steady 25-25 knot winds and it would be nice to set up for that. That sets up for double the wind velocity over a 100% sail plan with half the force on the sails. This boat needs the jib to be working to reach in heavier winds.

I do have a 3rd reef point set up but have never used it.
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