A directionally-stabilized waterjet steering system for a marine vessel having a vessel structure and steered by an operator, comprising: a steering deflector with a center position; a tiller arm connected to the steering deflector; an input device; and a centering module connected between the tiller arm and the vessel structure, the centering module having a center detent corresponding to the center position, whereby the operator senses the center position of the steering deflector through the steering input device.