The base is 20mm thick.
Not sure on weight ,I don't have the board with me right now.
Front rocker 20mm ,300mm long and back rocker 6mm ,100mm long.
It has a little flex but not much because I fibreglassed it top and bottom with 4oz. glass.
The concave is 8mm deep 200mm wide and 2/3rd of the lower flat length long (1000mm).
Tapered the rails 50mm in, down to approx 8mm wide round.
I did my rails and concave shaping with a 36grit sanding disc on a 4.5 inch grinder( but I use a grinder every day at work on steel and if not careful it will eat the wood) then used a rotary sander with a 60 grit disc and then finish shaping with a 120 grit.
I used gorillia glue to glue it together with vise grip quick clamps across and weighted and c-clamped down with plastic covered wood 2x4 on to a wooden work bench cover in poly.
Yes some of the sugar is visible but I think some of it will fade with water exposure and use. It feels very grippy.
Still have not tried it ,there is still ice on my go too lake,hoping to use this weekend.