The observation of the three-dimensional geometrical evolution of mooring chain links exposed to the marine environment can be achieved by using 3D scanners. Successive surveys make it possible to precisely identify the location, shapes and quantities of material loss by corrosion or fretting in interlink contact areas. However, the comparison is only possible after an alignment of the obtained scans, because they are not expressed in the same reference marks. The usual point cloud alignment algorithms not being adapted to the expected accuracy, the carried out work implements a new algorithm based on the iterative closest point method (ICP). The developed iterative process of alignment, moves the point cloud corresponding to the aged link onto the new link, after detecting and deleting the points located in the areas of localized material losses (pitting corrosion or wear), and after adding an extra layer on the remaining surfaces, of a value corresponding to the loss of material by a generalised corrosion assumed to be constant. The tests carried out on perfect meshes from CAD constructions show a convergence of the alignment process towards a sufficient precision with regard to the work objectives.