Angus
Just do what the RM and RA sailors, where all carbon has been the norm since adam was a lad. Have a plug in receiver ariel that has the normal length outside the boat, the rest is in the boat. This is achieved by running the ariel lead in the outer tubular sheath of an model aircraft rudder snake, available at all model aircraft shops. The lead outside the boat is either run up the back stay or is in whip form using the inner part of the snake as support or is lead up the shrouds.
If you can’t make sense of that give me a ring.
Bill