Green ‘012 Spines -During the flutter power stroke kick, there is no difference between Blue spines or Green spines, and the blade will flex sixty degrees 'toe down'. During frog kicking Green spines cause the blade to remain flat (flex zero degrees 'toe up') during the pushing away power frog kick for slightly improved glide distances. During the flutter and dolphin return kicking, a fin equipped with Green spines will remain flat in the 'toe up' direction (during the return rearward kick direction) and enable the user to add propulsion thrust during the return kick stroke if the user has sufficient strength. Because Green spines do not allow the blade to flex in the 'toe up' direction, rapid flutter kicking while exerting force during both the power and return stroke may be a more demanding experience, although the benefit is that greater propulsion speed is possible.
