Wise partner on horse in English coastal area (9,3)

I believe the answer is:

morecambe bay

'english coastal area' is the definition.
(bay in northwest England)

'wise partner on horse' is the wordplay.
'wise partner' becomes 'Morecambe' (Morecambe and Wise were a comedy double act).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'horse' becomes 'bay' (bay is a kind of horse).
'morecambe'+'bay'='MORECAMBE BAY'

'in' is the link.

I've seen this clue in The Telegraph.

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