A predictive shock alert warning system (SA) installed adjacent a body of water and monitoring a voltage level present in the water to alert persons in or about the water the water when the level is approaching, or reaches or exceeds a threshold that will produce a dangerous shock to a person. The system comprises a plurality of probes (1-3) placed in the water, each probe monitoring the voltage level in a zone (Z1-Z3) of water surrounding the probe and producing an output representing the voltage level for the respective zone in which the sensor is placed. An apparatus (100) processes the respective signals from each probe and triggers an alarm (13) when a voltage approaches, reaches or exceeds the danger voltage level.