Boats are visible in snap master photographer brought up (7)
I believe the answer is:
sampans
'boats' is the definition.
(sampan is a kind of boat)
'are visible in snap master photographer brought up' is the wordplay.
'are' becomes 'a' (short for 'are', historical unit of measurement).
'visible in' is an insertion indicator.
'master photographer' becomes 'ms' (I can't justify this - if you can you should believe this answer much more).
'brought up' shows that the letters should be reversed in order (in a down clue, letters go up).
'snap'+'ms'='snapms'
'a' going within 'snapms' is 'snapmas'.
'snapmas' backwards is 'SAMPANS'.
Can you help me to learn more?
(Another definition for sampans that I've seen is " Chinese skiffs".)