Channel so nearly consumes naval hero (6)
I believe the answer is:
nelson
'naval hero' is the definition.
(I've seen this before)
'channel so nearly consumes' is the wordplay.
'consumes' says the answer is hidden in the clue (the answer has been consumed by the clue).
'NELSON' is hidden within 'channel so nearly'.
(Other definitions for nelson that I've seen before include "Horatio or Mandela?" , "Hero of Trafalgar Square" , "Admiral called 5" , "Lady Hamilton's admiral lover" , "Sea-lord who loved Lady Hamilton" .)