Have been building a timber surfski. I started out with a Pax 20 hull as the basis for the project but have played around with the sheer line an beam width/location.
I'm aiming for 15kg but that might be a bit optimistic. 16kg should be achievable.
Eventually, I plan to add stripped decks using Paulownia to keep weight down but will probably fix temporary ply or skin decks for in the first instance.