The study presents results of several years of research into the issues of the creation, opera- tion and specificity of the operation of Baltic lightvessels – useful at the time of the lack of stationary lighthouses on shipping routes. The described ships were characteristic shipping marks of Denmark, Sweden, Finland, Russia and Germany at the turn of the 11th and 20th centuries. The specificity of the units, also called lightships, required the use of research methods such as historical analysis and synthesis, induction and geographical method. The presented paper is only a part of the Scandinavian problems that arose during the oper- ation of the specific entities described. A number of scientific papers have been delivered at both national and international conferences. Archival materials related to the operation of lightships were acquired by the authors in the German, Swedish and Russian state archives.