Underwater Bilge keel repairs

A bilge keel is used to reduce a ship’s tendency to roll. Bilge keels increase hydrodynamic resistance to rolling, making the ship roll less. Bilge keels are passive stability systems.

Bilge keels have a major advantage in their low impact on internal ship arrangements. Unlike fins, bilge keels do not have any components inside the hull that would adversely affect cargo or mission spaces.

Like fins, bilge keels have the disadvantage of increasing the hydrodynamic resistance of the vessel, thus hindering forward motion.So when a bilge steel is damaged this can result in aditional energy consumption and secondary cavitation on the propulsion and steering gear due to the altered waterflow. In these cases a Diving team repairs the bilge sheets by means of underwater cutting and welding getting them back in to shape.