Measuring a Tri-Radial Spinaker

[alma]

Hi Everyone
I am new to this forum and I suppose this question has been asked before so please excuse me if it has.
I have just obtained a Tri-Radial spinaker of roughly (very roughly) 500 sq ft but I need to have a fairly accurate measurement before I can use it.
Could anyone explain a step by step procedure I can use to measure the area of the spinaker.
Thank you very much.
J Will

PS. I am new to sailing so this is a big learning curve for me.

[Joli]

SA for a kite is 1.8*J*I. Measaure your I and J or look them up for your boat.

[alma]

Thanks Joli for the info. Greatly appreciated. However what I am after is how to measure an existing spinaker area. I believe there is a method of lying the spinaker on the ground and folding it in a certain way and taking varies measurerments to ascertain its total overall area. This is the method I would like to know how to do.
Thanks again

[Joli]

Roughly it will be SL * SMG *1.8.

Fold it in half and measure across. = SMG = spinaker mid girth or .9 * J
Measure from the head to the tack rings. = SL = spinaker luff length or I

Here's ours 1.8*26 (J) *86 (I) = 4024 sq ft

I'm not sure our assy is full size, it may be slightly smaller. The sailmaker may have used a 1.65 multiplyer but I've never checked or cared. The 3/4 sym kites are probably full size but again never checked. The 1.5 and 2.2 sym kites are surely smaller but again I've never checked. We don't race enough anymore for me to worry about it.

Curious, why do you care as long as it fits your fore triangle? Measure the SL and see if you can hoist it. Even if it's over by a few feet it won't matter unless you're racing and need it to measure in.

[alma]

Hi Joli
Yes it is for racing H28 can you believe it. There is a fleet at my yacht club that race regularly however they do have limitations on sail sizes for mains and spinakers and foot and luff lengths for jibs. The info you have provided will help me ascertain whether my spinaker falls into the OK catergory or not and has to be re-cut. At the moment it sets good in up to 15 knots broad reached but as I mentioned I want to comply with the regulations the fleet has adopted.Anyway thanks heaps you were a great help. If you have any other info regarding sail measuring it would be a great help. Thanks again.
Regards
J Will

[Joli]

Not a problem, if you take it to your sailamker he'll measure and certify the sail for you. If it's slightly oversize lay it on the blacktop or give a quick spin in the dryer, it'll fit.

Good luck racing and have fun.

Joli

Originally Posted by alma

Hi Joli
Yes it is for racing H28 can you believe it. There is a fleet at my yacht club that race regularly however they do have limitations on sail sizes for mains and spinakers and foot and luff lengths for jibs. The info you have provided will help me ascertain whether my spinaker falls into the OK catergory or not and has to be re-cut. At the moment it sets good in up to 15 knots broad reached but as I mentioned I want to comply with the regulations the fleet has adopted.Anyway thanks heaps you were a great help. If you have any other info regarding sail measuring it would be a great help. Thanks again.
Regards
J Will

[bayview]

Originally Posted by Joli

Roughly it will be SL * SMG *1.8.

Fold it in half and measure across. = SMG = spinaker mid girth or .9 * J
Measure from the head to the tack rings. = SL = spinaker luff length or I

Here's ours 1.8*26 (J) *86 (I) = 4024 sq ft

I'm not sure our assy is full size, it may be slightly smaller. The sailmaker may have used a 1.65 multiplyer but I've never checked or cared. The 3/4 sym kites are probably full size but again never checked. The 1.5 and 2.2 sym kites are surely smaller but again I've never checked. We don't race enough anymore for me to worry about it.

Curious, why do you care as long as it fits your fore triangle? Measure the SL and see if you can hoist it. Even if it's over by a few feet it won't matter unless you're racing and need it to measure in.

Now thats what I call a spinnaker. Do you set it when sailing short handed and do you set it with a snuffer?

Regards.