I rember once checking to see if there was a party below, noting a pair way off the line, dropping the rope and then being admonished for not shouting 'below'.
How about flake it into a poly bag ? kept in a pocket - and clip it to the descender on a sling - works a treat when there are loads of snags like saplings sticking out all over the place - or sea water for the rope to land in - just put a knot in the ropes so you know if the end is coming up.