HiFly Successfull ????
Yes if you liked sailing boards made of washing up bowls.
They were great if you wanted to drag kids about over shingle sand glass bricks etc etc.Think the term was variable rocker line.They bent quite a bit;especially in warm climes.
Sailed my mates (555; anybody else remember that !!!) and you could feel it flexing over chop/ripples.You could even look behind you and see boards vibration affecing wake ! (Really !)
They did fill a market at time though ! (Think they had first "fat head" sail too !;the 555 came with a 7.2 (unheard of those days;it was a 6.6 regatta with a "fat head" )
Couldn`t match Sailboard Sport or F2 Lightning though !
All gone now !!!????