I've been kiting a bit over 2 years.
I designed up my current board in August 2016 and love it, I was inspired by reviews and video of the Ocean Rodeo Mako in action. High concave, semi eliptical.
So as I do a bit of 3D design and printing as a hobby (I'm fluidity on thingiverse too), I designed a couple of boards and tested them. The first one didn't have much rocker or concave. The second one I put more concave (25mm) into the board and more rocker. Since then it's been the board I play with in waves and that gets me cutting hard up wind for endless jumps.
After almost a year and a half with this board though, I feel the need for another one with a bit more rocker and a smaller foot print to use on those choppy high wind conditions where currently I have to back off on kite power and keep back foot pressure up. The idea is to have it lift over chop without so much risk of catching a front edge. I'll lose a bit of up wind ability but I have so much on my current board that it's just ridiculous.
The way I design is that I use a program I wrote to produce a cylinder and then I use some additional maths to produce distortions into the cylinder before taking a slice out of the surface that will represent the underside of the board. So in this case I pinch the middle of the cylinder to get a high concave in the middle of the board (but flatter and easier to spin the board around on the tips), I put a deviation on the centre line of the cylinder to straighten and produce neutral rocker and then I apply another formulae to this spine to give rocker that smoothly increases towards the tips in both directions. Then I make a block in the outline I want for my board and take a slice of it's intersection with the cylinder's surface end on. From this slice I take transverse cuts at about 120mm apart and save them as DXF files. I import these into inkscape set to A0 paper size and use them to produce forms to shape the under side of the board. I export these with a DXF half outline of the board into my A0 PDF and get it printed actual size at a commercial print shop.
Then I get a good sturdy length of wood plank and route channels on one surface 120mm apart from each other.I spray glue the forms to some cheap MDF or other wood and use my scroll saw to cut them out, then I glue them into the routed channels on my wood plank. Next I glue at least four at a time paulonia wood strips to each other and hot melt glue to my forms + belt tie them down to my forms and plank. After about a week of evening tinkering, the wood is all in place and I can sand the deck then epoxy cover with some basalt, print pattern polyester fabric and s-glass. Once the deck covering is cured I knock off the hot melt glue, clean and sand smooth the underside then epoxy composite coat the underside after routing out holes and fitting the handle and footstrap mount T-nuts.
So here's some snapshots of the CAD for my latest design, any thoughts on the amount of rocker for strap riding?