The Search and Rescue Radar Transponder (SART) operates in the frequency range from 9.2 GHz to 9.5 GHz. The SART is used on conventional and, partly, nonconventional vessels in search and rescue operations at sea. It is also used, to a certain extent, on inland waterways, rivers and lakes. As for their construction and design, SART transponders are self-contained, portable units. With regard to their technical characteristics and design requirements, they comply with the regulations of local registers of shipping when fitted to new-build vessels or in case of subsequent installation. This paper presents the influence of the real-life conditions to the SART radio horizon. When the device is operated on various survival crafts and life-rafts, the actual ranges achieved under dynamic conditions, depending on the changes in the SART antenna height, differ very much. However, it can be noted that the application of the SART in real-life conditions in practice does not achieve the results required by relevant recommendations. The paper also provides suggestions for potential improvements in SART operation and use.