No, because stiffness comes with thickness ^3, the middle of the board is way more stiff than tips, so if tips are 3mm and mid 12mm, thats way more than 1 layer of carbon is providing.
Plus, whan landing, its a console with heaps tension on bottom. None on top. The board buckle under the pads coz on compression, not tension. They also break wide open under pads on bottom by tension.
The pic is assuming uniform Ibeam, not a reinforced beam, and most boards are not uniform as you know.
Remember, we are making a reinforced ibeam with top glassing and bending wood. So the glass is always tensioned on top. Like a pre cast concrete (when concrete is put on compression, with tensioned steel).
So, yeah, its not that simple as on pic. As you said, it is not even uniform load. Depending on the edging, 1/3 of the board might be above water, so the load is really this (WIP, could not find any on the Net, so will make one for you in due course:)
The pics are also telling you that the support is fixed, non movable. Which is wrong, coz our foot is moving in straps (well maybe not in boots; ). What we have is this sign as on B!
Which totally messes the diagrams when you have a dynamic, non uniform load with non fixable support. Civil engineering 1o1. We also talking hydro dynamic here which wasn't my forte on uni.
Plus, Kosta is wrong on bridges as well, the reason why bridge is 45 degrees is tensioning steel via load distribution for stability. Nothing to do with flex, but with tension. We do not want a bridge to flex, coz this creates dynamic forces, and that creates unknown vibrations. We want steel to be in equilibrium of tension, no compression, no flex, no vibrations.