Although director James Cameron is busy finishing up two new Avatar movies, he has retained his interest in marine archeology. The rumor is that he has recently learned that, when HMS Ark Royal was torpedoed, a number of the Swordfish that went to the bottom with her carried experimental R.D.F. sets. Thus the wreck might be a valuable source of information about British R.D.F. development, both shipboard and airborne. Cameron is negotiating with the Royal Navy for permission to film an underwater documentary. The working title is "Radars of the Lost Ark".