Vessels: most at base, after refit (10)

I believe the answer is:

steamboats

'vessels' is the definition.
(steamboat is a kind of vessel)

'most at base after refit' is the wordplay.
'after refit' is an anagram indicator (letters refurbished or refitted).
'most'+'at'+'base'='mostatbase'
'mostatbase' is an anagram of 'STEAMBOATS'.

I've seen this clue in The Times.

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