36 ? you're younger than me , lighter than me and get better surf !
so you'll do fine on a 5'8" as Xtremeliquidshredda said ! Any bigger it will feel like a boat !
Regarding volume : Keep in mind the Dwart carries more under your chest and the nose,with the widepoint more forward than a Piranha so It catches waves easily and generates instant speed on takeoff . The rusty "quadratic formula" places the fins closer to the stringer . So you get the speed of a quad with the pivot of a thruster. I like the stretch quad template. I haven't ridden it as a thruster.
~ good luck
Thank you again mark
I will be in mind your good advice
I decided on the 5.8, now I just need to know where can I buy. The truth is that I prefer the boards made in USA, but I can't find any store that send to Spain and have fCS system