Path optimization is one of the main factors that determine the safety and efficiency of ship navigation in the Arctic. This paper describes a new wave-based ice routing approach. Unlike cell-based approaches that use a predefined grid to describe possible ship movements, the proposed algorithm is cell-free and based on the method of isochrones, while all calculations of isochrone propagation are done using geo-algorithms and operations with geo-polygons. We also consider the boundary conditions (ocean-land masks or vessel drafts) not by means of the depth matrix, but checking the intersections of polygons. This polygon-based approach allows taking into account such special features as the discontinuities in ice cover, ice leads, and fractures, which in practice are quite important part of ice routing task. To implement the developed routing algorithm, we used a standard programming language, but any GIS software with the built-in standard procedures may serve for this purpose. To prove the applicability of the developed approach, we conducted and described in the paper the case study of optimization of ship path in the Arctic.