Thanks! I'll bet CNCd ABS plastic ends up lighter and stronger than rotomolded. Also the plywood in that prototype cost 20 dollars. It snaps together in 5 minutes. There are tabs built into each component.
What's my point beyond patting myself on the back? I'm not sure rotomolded is the way to go. Big and heavy. And with a smart design assembly is not time consuming... I.e. Expensive
Lee, I certainly didn't intend to dismiss your innovative design. I guess I was thinking that your design would need a lot to turn into a production unit (if that is your intention), and if delivered in a flat-pack configuration would presumably require accurate use of adhesives, while needing some refinement of the method of attachment to the akas.
I don't think anybody would expect rotomoulded hakas to be lighter, but by judicious use of "scuppers" to bond top and bottom surfaces, a strong and low-maintenance product could result, which would probably meet the requiredmens of the gret majority of Island owners.
I guess spinal boards are already on the market, but suppliers (on eBay at least) seem to price shipping costs at the "delivered personally by limousine" category which far exceed the product cost.