I am assuming that you are talking about the jib
You are correct to a point. Let me go a bit further in the explanation.
Pull you genoa/jib off the furler
, take it home or to someplace you can lay it out flat. Find the mid point of the luff, ie the part on the forestay. From there, take a string and go to the clew, ie where the sheets attach. Now take a sharpie and draw a line
on your sail where the string is out about 2' or so. Put sail back on furler
What you want now, is when you are sailing, generally speaking, the sheet line
up with the sharpie line
you drew on the clew of the sail. The yes, lighter winds, a bit more forward. middlish winds, I'll say 8-20 or so, on the line, and heavier, you want the sheet to be back a bit. For my boat, I find the light winds, line up the sheet and sharpie line, 8-15 a bit back, ie 2-4" back for the carr, and over 15 or so, double distance, or about 4-8". Your boat may very well be slightly different.
This is where having line control carrs is really nice, you can micro adjust the carrs for best performance out of you sail. These are also IMHO more important for folks with furlers
that cruise. As you furl the genoa in, you need to move the carrs forward. with line control, you pull on a line, carr moves forward, you might need the help of a winch
, or loosen the sheet some, then pull, retighten sheet. With pin stops that most cruisers seem to have, you have to go forward on the side deck, pull the bleeping pin, and hope you can slide it forward a foot or so per jib
reef. at least it is a foot or so going from a 155, to a 140 to a 130 on my boat! A 110 is about 6'ish feet forward from the 155, ie about 13' IIRc from bow vs 19' for the 155. I have also marked the foot lines on my genoa carr tracks. so I can set them as I change head sails too. You would want to do something similar with a furling
sail, 6 wraps the carr is at 13' no wraps 15', 12 wraps 11' or some such amount for "YOUR" boat.
In the pic below, you can see the sharpie line dispite me having a carbon 155. you can also see that on this reach I am on, the carr is a bit back. ut being as I am on a reach into a start line, so be it, the carr is setup for the upwind start. If I was to stay on that course for more than the start sequence, the car would go forward some. Along with letting the main out some too, making it so I had less heel for this pass.
is a link to how I installed my line control carrs.
Hope some of this helps.