The Author presents research problems related to the computational algorithms implemented in the software applied in marine navigation electronic devices and systems, such as GNSS (GPS, GLONASS, Galileo), AIS, ECDIS/ECS, and other marine GIS that deserve to be collected together. He argues that there is an urgent need to develop and standardise new geodesic-based navigational methods, algorithms and calculations. The geometry of approximated structures implies the calculus essentially, in particular the mathematical formulae in the algorithms applied in the navigational electronic devices and systems. The question he ask affects the range and point in applying the loxodrome (rhumb line) in case the ECDIS equipped with the great circle (great ellipse) approximation algorithms of given accuracy replaces the traditional nautical charts based on Mercator projection. Moreover, the navigation based on geodesic curves and connected software of the ship's devices (electronic chart, identification, positioning and steering systems) gives a strong argument to research and use geodesic-based methods for calculations instead of the loxodromic trajectories in general. The paper concludes with summary of findings related to discrepancies between theoretical background, good seamanship practice and real actions taken by navigators.
