Fictional sea captain's exclamation to a sailor (4)

I believe the answer is:

ahab

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'fictional sea captain's' is the definition.
'Ahab' can be an answer for 'captain's' (Captain Ahab appears in Moby-Dick). I am not sure about the 'fictional sea' bit.

'exclamation to a sailor' is the wordplay.
'exclamation' becomes 'ah'.
'to a sailor' becomes 'ab' (abbreviation for able seaman).
'ah'+'ab'='AHAB'

Can you help me to learn more?

(Other definitions for ahab that I've seen before include "sea captain" , "Melville's whale chaser" , "Captain -, pursuer of Moby Dick" , "Moby Dick's pursuer" , "Captain hunting Moby Dick" .)

I've seen this clue in the Evening Standard.

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