Steve asks why an eight in the number !
-and he’s not the first to ask that question !!
The answer is to be found on page 159 of Ian Proctor’s ” Sailing – Wind and Current “
Apparently the flow of air across a sail tends to ‘stick’ to the sail numbers but with an 8 , and only an 8 ,the sticking produces a vortex which accelerates the air flow as it leaves the bottom part of the 8 .
While this effect has been known to W sailors for years the physicists only recently discovered it and has resulted in them building a huge tunnel to the north of Geneva in the shape of a huge 8 in an effort to reproduce conditions during the Big Bang !