This article is an introduction to the analysis of human reliability in specific anthropotechnic systems, such as marine power plants. The human factor is discussed as one that is responsible for creating dangerous situations during the operation of offshore technical objects, mainly sea-going vessels. Besides, we indicate the place of a human being in marine technical systems, his specific qualities and interaction with the environment. Selected classifications of human errors are given as well as their particular causes. Then we present a model of an autonomous system referring to the human being, based on Mazur’s concept. Besides, potential fault nodes resulting from that model are specified. We show examples of quality and quantity models that are helpful in an analysis of the reliability of the human, an element of such technical systems as marine power plants. Final remarks include possible applications of mathematical models herein presented in analyses as well as some restrictions in the use of these models. Emphasis has been put on essential difficulties in utilizing simulators for the examination of the reliability of the human considered as the operator of a marine power plant. These difficulties are due to a variety of interactions within the system (the vessel) and relations with the external environment