An automated laser cutting process shall be achieved under water – in a depth of 2 to 6 metres. This new area of applications for separating steel under water, tremendously contributes to the competitiveness of small and medium sized companies. So far, the divers principally perform separation and reparation work manually, and light bow oxygen cutting is said to be the most important process. The demands for this system: A qualitatively high-quality cut requires precise and smooth guiding of the laser cutting head alongside the sheet pile wall. Therefore, the guide rails of the system need to work problem-free both underneath the waters surface, and at high pollution levels. All components in use shall be corrosion-resistant for the purpose of a permanent under water use. Conventional systems, which required lubrication, have not been appropriated according to the environmental conditions. The used iglidur® J plain bearings in combination with corrosion-free drylin® ZLW linear axes and drylin® E Nema motors with the protection class IP68, offer the optimal solution for a permanent under water application.