When it comes to construction of waveboards also here the saying is right that the chain is as strong as its weakest link.
All production boards are using EPS which is an open cell foam, light and a great foam te press into a mould to pop out a board. This foam is very soft, to increase the durability the manufacturers are using sandwich constructions to improve durability either PVC, wood or bamboo. Main problem here is that a sandwich construction like wood or bamboo top and bottom creates a lot of stiffness in length direction this affects the performance of the boards negatively as it makes the boards more nervous. Another main difference between production waveboards compared to surfboards is that the open cell EPS has a lot of air in it as it is open cell
this will give the boards more buoyancy.
Coming back to the weakest link if you have 0.3mm wood veneer sandwich but 2" of soft EPS foam it not if but when it delaminates or breaks, the weakest link here is the EPS.
Here in Cape Town there is a company that Manufactures Custom Waveboards and they combine the best of both worlds. They use a Styrofoam HD closed cell core with a bamboo stringer.The heel sides are reinforced with a Balsa wood in various thicknesses from 3mm up to 20mm. There is hardly any weight increase and the boards have a huge amount of flex. Due to the close cell another advantage is that you can get the boards at least 1 size bigger than you would ususally choose with a production boards with all the added advantages of a bigger board.
We sell them here in Cape Town and they are popular as these are high performance Surfboards but extremely durable. The locals here ride almost on a daily basis in the harsh conditions here the boards do get a beating. Have a look at the stuff they do and the flex in the boards it is crazy.http://www.xeleratorkiteboarding.blogspot.com/2011/09/what-size-and-shape-waveboard-should-i.htmlhttp://www.xeleratorkiteboarding.blogspot.com/2010/11/xelerator-epic-custom-waveboards.htmlhttp://www.youtube.com/watch?v=yRpSkl7EffI&feature=g-upl
Hope this is some usefull information regarding the construction of modern kitewaveboards.
Have fun out there!!