Nautical rope or chain (5)
I believe the answer is:
cable
I believe this is a double definition.
'nautical rope' is the first definition.
(I've seen this in another clue)
'chain' is the second definition.
(thesaurus)
(Other definitions for cable that I've seen before include "A message transmitted" , "Communications wire" , "Strong thick rope made of twisted hemp or steel wire" , "Rope; message" , "Telegram; thick rope" .)