The bottom concave is at its deepest right between the feet to maximise lift reducing the need for foot movement. The fins are also pushed forward to allow for a ‘glue footed’ stance on the board. 

The tail rocker has more curve than most modern shortboards whereas the entry rocker is quite moderate so that drive and planning speed is maintained between your feet. There is a slight double concave on the deck which then decreases the thickness of surfboard foam between the surfers heels and toes and the water surface below.

As a result of the stinger tail the plan shape is more parallel immediately forward which adds grip while the shortened concave adds lift.