Mark _australia said..
Cost. Foam makes new models easy to produce .. but slight tweaks for costly mould changes made it hard to have a range of hollow boards.
then labour cost maybe for more complex layup, trimming halves and then bonding halves properly.
I think foam sandwich is the best blend of cost vs durability vs ability to change shape if needed and that's why it's prevailed.
I've seen some great DIY hollow boards but I think the current mass production of them is a response to the trendiness of wing / DW and wanting to have something new that the other companies don't have. I hope it doesn't translate to $5000 windsurf boards soon.
Yes it was all about price. They were going to retail for USD$4000 back in 1991 (about $10000 today), the Japanese were snapping them up. They were too expensive to make. The best shaper and best windsurfer in the world were involved.
If I was too make a hollow board today it would be 3D printed and easily modified. I have plans for a basic monocoque that a number of different shapes can be fitted to. You could easily have 3 different slalom/speed boards using one monocoque.
