the core it has been found that this is a more reliable method of controlling permeation than the current method of making the control lines less permeable heretofore suitable materials have not been found for this purpose by flushing the permeants from the core the permeant hazard is minimized this has been shown to be more effective than attempting to eliminate the permeant altogether moreover the present apparatus and method can be applied to the many existing umbilical installations without taking the umbilical out of service and without changing the umbilical configuration fig3 illustrates a typical installation showing an umbilical in combination with the apparatus of the preferred embodiment of the invention for practicing one of the novel methods disclosed herein as there shown the elongated umbilical 70 includes an upper end 71 and a lower end 74 for purposes of discussion the umbilical of fig2 is utilized in the assembly of fig3 in a typical installation the upper end 72 of the umbilical passes through a bend stiffener having a hang off flange 76 for securing the stiffener to the surface platform in the manner well known to those skilled in the art in some cases the stiffener 76 is cast directly onto the umbilical outer sheath the outer end of the umbilical is then received in a snag resistant armor termination armor termination 78 in some cases the hang off flange may be above the termination 78 as desired depending on the particular application the outer sheath 64 and.