A new concept of determining the visibility range of the objects in the scattering media based on the ideas of optimum processing of image is presented. The practical realization of this concept is described in the form of the program for calculation of maximum ranges of detection and discrimination of underwater objects (including that through the water––air interface) with the help of passive television and active laser-television observational systems. The characteristic features of the program for personal computer complexes as well as of the specially–developed convenient few–parameter models of the optical characteristics of water, interface, and atmosphere implemented in the program are described. The certain examples of calculations of maximum visibility range are presented. The general character of the concept and modularity of the program make it possible to extend substantially its capabilities.