Vessel turning about? (1-4)

I believe the answer is:

u-boat

'vessel' is the definition.
(I know that U-boat is a type of submersible)

'turning about?' is the wordplay.
'turning' is an anagram indicator.
'about' with letters rearranged gives 'U-BOAT'.

(Other definitions for u-boat that I've seen before include "German wartime submarine" , "German World War One or World War Two submarine" , "German WW 2 sub" , "Take pool exercise" , "Submersible warship of WWII" .)

I've seen this clue in the Evening Standard.

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