A system substitutes digitized camera images for human vision, in determining the presence or absence of rip tides among sea water wave patterns at a public swimming beach. Computer analysis of these images involves image pre-filtering that enhances the telltale signs of rip tides, before the digital data is processed for classification as NORMAL or RIP TIDE. The classification itself can proceed along by expert systems which mimic the manner in which a human observer performs the detection; or by building a neural network, that determines its own classification criteria for identifying rip tides.