摘要:AbstractToday, electromagnetic waves are the basic medium for all communication tasks. This applies also to navigation, where the most commonly waves have lengths measured in centimetres (radar, GPS) and longer, such as the waves used in the AIS or DGPS technologies. Navigators are mostly interested in the communication functionality of the used systems, i.e. such factors as range of the system and signal-to-noise ratio. This leads directly to increasing the transmitters’ power. However, it is important to bear in mind that the electromagnetic field can endanger human health, therefore, establishing the level of radiation both on vessels and near the shore transmitters is crucial in this context. The experience of authors shows that the knowledge of the most of navigators hereupon is not large. From this result extremely irresponsible behaviors of one persons, as well as inexplicable phobias others.This article presents the subject using the example of the electromagnetic field present near a lighthouse emitting AIS and DGPS signals. Relevant measurements were made at the Rozewie lighthouse by certified laboratory of Maritime Institute in Gdansk according the polish standards and internal, certified procedures. Results of the measurements were related to the national and European standards for electromagnetic field measurements in the context of occupational health and safety.