I know they were laying up hi-end power boats with little graphite pockets that could be cleaned out later that left a dimpled finish. Supposedly they do go much faster.
Cant remember which but the Hurricane or Spitfire had some tests done where they re-done the rivets so they were flush with the skin of the plane. Supposedly to reduce drag, problem was, it was actually slower like that and stayed so until they glued lentils where the rivet heads were.
Yes.....Lentils!
