Modern spey fly lines were pioneered and developed by Jim Vincent, with the help of other proficient spey casters. Spey casting requires a different design of fly line than regular overhead casting with a weight forward line. The head length needs to be longer to enable the spey cast to "anchor" easily and it needs to be much heavier than a standard fly line. For example, a regular #8 weight forward line weighs around 210 grains at 30 feet. The RIO™ WindCutter® #8 (7/8/9) has a head weight of 525 grains.