Abstract: A system for graphic representation of a vessel's position on the Mercator map, comprising a velocity and drift angle sensor and a heading sensor which are connected to a computer to compute the longitudinal and latitudinal velocity components. The computer has its outputs connected to respective binary multipliers which, in turn, are connected via a storage to a nonlinear converter and, via respective circuits incorporating frequency dividers, to integrating drives of a plotter intended to indicate the position of the vessel on the Mercator map. The nonlinear converter is intended to reproduce electric signals in the form of trigonometric functions and has its correction input connected to an output of an approximator of the correction for the meridional minute length at the location of the vessel. An information input of the nonlinear converter is connected to an output of an adder.