Simplicity in sea service (4)

I believe the answer is:

ease

'simplicity' is the definition.
(synonyms)

'in sea service' is the wordplay.
'in' says the answer is hidden in the clue.
'EASE' is hidden within 'sea service'.

(Other definitions for ease that I've seen before include "Allay" , "Facilitate; repose" , "Comfort; simplicity" , "Absence of effort" , "No trouble" .)

I've seen this clue in the Evening Standard.

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