Ignores the fact that the captain's diminutive (5)
I believe the answer is:
skips
'ignores the fact that' is the definition.
I can't tell whether this defines the answer.
'captain's diminutive' is the wordplay.
'captain' becomes 'skip' (short for skipper).
'diminutive' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'skip'+'s'='SKIPS'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for skips that I've seen before include "Large containers for rubbish" , "Waste containers" .)