The myth of the venturi effect

The nonsense is being posted thick and fast out there on the surfing forum waves.Today we have some supposedly well respected and masterful surfboard shapers on Swaylocks design forum peddling the myth of the VENTURI effect and how it supposedly speeds the surfboard up by accelerating water between the fins . Here's the threadThe venturi fin effect as a means of surfboard thrust is a long dead concept which has been shown to be incorrect countless times, but it's still out in some kind of living dead zombie form due to the existence of certain old unreprogrammable cranium filler out there.The news is once again: The venturi effect doesn't work with surfboard fins , as constricting the water flow slows it down, or to be more exact it accelerates it in the direction the surfboard is moving in instead of leaving it behind as undisturbed as possible this causes an increase in drag and slows the board down.The Swaylocks gumbies who are currently mumbling on about venturi effect on one of Bill Thraikill's double fin setups are not even talking about it in the context of an enclosed flow, which makes it even more riduculous ! They are thinking that two fins parked side by side will 'accelerate' water flow through the constricted slot between the fins and speed the board up. Get the GPS units out you big talkers it might teach you something if you actually measure speed.