Closely examine small vessel during holiday at sea (10)
I believe the answer is:
scrutinise
'closely examine' is the definition.
'scrutinise' can be an answer for 'examine' (I've seen this before). I am unsure of the 'closely' bit.
'small vessel during holiday at sea' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'vessel' becomes 'tin' (type of container).
'during' indicates putting letters inside.
'holiday at sea' becomes 'cruise' (holiday on a ship).
'tin' put within 'cruise' is 'crutinise'.
's'+'crutinise'='SCRUTINISE'
Can you help me to learn more?
(Other definitions for scrutinise that I've seen before include "Examine closely - runs cities (anag)" , "Carefully examine" .)