Modern windsurf sails are very good but they have also progressed alongside board development.
Let's runthrohg a few of those issues.
On short wave boards we use a very upright stance but the rig still moves aft as we start to plane, bringing battens more parallel to the air flow.
The aspect ration of sails changed so that our masts were shorter and that was to help with swing weight in transitions and for when a wave board or freestyle board is in the air and rotating.
Those windsurfers who race will have a different agenda. Some newer race sails are now high aspect again and that's because of foiling - which generally happens in much lighter wind.
We might also see tighter leeches on foiling boards, not just because they are more powerful in light wind but to create more leverage or downforce to use against the upward lift from the foil.
Battens are already tapered to help shape the sail, but they tend to take up the cut of the sail rather than to force a new shape into a sail with a bad cut. Batten ends become more critical when used with cams because of the risk of breakage and because of the need for cams to 'tack' (rotate efficiently) on the mast.
There's not much that hasn't been tried with our sail designs. But the latest news is that some foilers are using an MDM mast - and that's a new mast diameter that's half way between an RDM and an SDM. MDM stands for 'medium diameter mast'.
ka koncept 7m - 199x458 = .43
ka race 7m - 199x458
np racing evoxII 7.4 - 205x482 = .425
ga vapour 7.2m - 208x461 = .45
simmer scr 7m - 212x451 = .47
duotone warp 7m - 213x452 = .47
maybe im reading it wrong but here are the numbers. in order of boom length
Boom lengths are effected by the size of clew cut-outs. The clew cut-outs on the Duotone are smaller hence the boom length is longer. However if you put the Duotone on top of the KA, the luff and leach above the boom are almost identical.
Not necessarily, width of luff and general cut would surely have influence of chord or combination there of....
disclaimer: not sail designer, maybe one could chime in
"Aspect ratio is a measure of the ratio between the span of the wing to its chord. In most cases the wing chord is not equal along the length of the span which is why aspect ratio is most commonly calculated by dividing the square of the wing span by the reference wing area."
luff x luff / area.
in the case of the duotone v koncept they are both 7m sails. because the koncept has a longer luff the aspect ratio is higher ie. the boom length is shorter.
the sail spec verify that boom length is shorter also.
as a rule of thumb for a sail with a clew cutout shortening the boom length increases aspect ratio because it reduces sail area below the boom.