Thanks Krucifix, when you say more round is the neck more drag... What are you referring to? Wing tips?
I am sorry, I dont know the terminology. By neck I ment the long and narrow part from board to that ufo-shaped-wing thing on the bottom (I believe from some technical-ish picture that that part is called the strut
However, pretty much any object which moves with rapid speed in liquid object will suffer with this kind of drag. But more aerodynamically is the object shaped, bigger is the critical speed at which vortexes are being made. This si why some local Cessna has narrow wings, but supersonic F22 has wings quite wide.