An attempt to determine the impact of developing polynomial on the accuracy of setting down a ship's position coordinates based on measurements of two bearings has been ventured in this paper. A navigation structure consisting of two aids has been analysed. A ship maneuvering within a given area was setting down her position in respect to them. As a result of this, numeral accuracy indexes were calculated. They gave principles for conclusions regarding the impact of the distance between the aids of navigation on the accuracy of setting down the position’s coordinates.