Source of present British managed boat (4,3)
I believe the answer is:
bran tub
'source of present' is the definition.
The definition suggests a singular noun which matches the answer.
'british managed boat' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'managed' becomes 'ran' (I've seen this in another clue).
'boat' becomes 'tub' (tub could historically mean a small boat).
'b'+'ran'+'tub'='BRAN TUB'
Can you help me to learn more?
(Other definitions for bran tub that I've seen before include "Gifts from here" , "Container for lucky dip" , "Lucky-dip container" , "place for a dip" .)