I am building a SUP. CNC cut blank. 15kgs stringerless. I am going to start buy glassing the whole board in 80g glass. This will keep the rocker and allow me to create a composite bottom.
So the bottom is going to be 80g glass then 55kg 2mm thick high density foam. 2oz innegra then 160g woven flax.
The deck will be 80g glass then 4mm Paulownia wood. 125g glass and cork standing area.