Abstract: An inlet grate mounted within the inlet channel of a watercraft, where the inlet grate contains a pivotally mounted divider vane disposed laterally across the inlet channel and biased by a torsional spring into a neutral position. The hydrodynamic forces of water moving through the grate alter the angle of the lateral vane, thus inducing equality of upper and lower inlet water volumes as well as pressure, proportionate to watercraft speed, thereby improving the efficiency of the watercraft's jet pump assembly without requiring the use of electromechanical devices.