There are many separated infrastructural objects within a harbor area that may be considered „critical", such as gas and oil terminals or anchored naval vessels. Those objects require special protection, including security systems capable of monitoring both surface and underwater areas, because an intrusion into the protected area may be attempted using small surface vehicles (boats, kayaks, rafts, floating devices with weapons and explosives) as well as underwater ones (manned or unmanned submarines, scuba divers). The cameras used in security systems operate in several different spectral ranges in order to improve the probability of detection of incoming objects (potential threats). The cameras should then have adequate range parameters for detection, recognition and identification and those parameters, both measured and obtained through numerical simulations, will be presented in the paper. The range parameters of thermal cameras were calculated using NVTherm software package. Parameters of four observation thermal cameras were also measured on a specialized test stand at Institute of Optoelectronics, MUT. This test stand makes it also possible to test visual cameras. The parameters of five observation cameras working in the visual range were measured and on the basis of those data the detection, recognition and identification ranges were determined. The measurement results and simulation data will be compared. The evaluation of range parameters obtained for the tested camera types will define their usability in the real security system for the protection of selected critical infrastructure of a seaport.small surface objects (such as RIB boats) by a camera system and real test results in various weather conditions will also be presented.