KIT33R said...It's heavier than a foam fibreglass board but still not too heavy. I guess that's why they use foam

Actually, one of my biggest complaints in trying to use standard surfboards for kiting is that they're TOO light. A super-light epoxy or fibreglass board sits high in the water, has very low mass and while it may turn easily, it gives you a bouncy, unstable feeling when your're riding it. You want the board to cut through the water, not sit on top of it.
I had a tuflite (epoxy) board a few years ago that was 6'2", super light and you would have thought to be a great kiteboard, but it felt terrible. After I got rid of it I replaced it with a Slingshot SST--same dimensions but a completely different board. The extra weight of the SST made it cut through the water better, it didn't bounce around and just felt all around far better than the tuflite board.
So, the fact that this wooden board is a bit heavier is actually an advantage and a benefit for a kiteboard.
Shapers who design big-wave surfboards and tow-in surfboards use similar construction techniques to ADD weight to boards (lead weights in the centre of the board) to add mass and give you better planing ability and more momentum. The LAST thing you want on a 20ft+ wave is to be bouncing around on a super-light board.