A submarine power cable including a conductor, an insulation system arranged around the conductor, the insulation system including an inner semiconducting layer, an insulation layer arranged around the inner semiconducting layer, and an outer semiconducting layer arranged around the insulation layer, and a polymeric sheath arranged around the insulation system, wherein the first section has a mechanically flexible sheath arranged around the insulation system, wherein the mechanically flexible sheath has a lower radial water permeability than a radial water permeability of any layer arranged outside the insulation system in the second sections.