Happen a storm will sink a famous ship (6)
I believe the answer is:
beagle
'famous ship' is the definition.
(ship Charles Darwin travelled on)
'happen a storm will sink a' is the wordplay.
'happen' becomes 'be' (I've seen this in another clue).
'storm' becomes 'gale' (a gale is a windy storm).
'will sink' is a deletion indicator (some letters sink or drop out of the word).
'gale' with 'a' taken out is 'gle'.
'be'+'a'+'gle'='BEAGLE'
(Other definitions for beagle that I've seen before include "hunting animal with smooth coat" , "Short-haired dog" , "HMS - was Darwin's ship; hunting dog" , "Hunting hound" , "Breed of dog in a glebe" .)