Day on lake in rowing boat gives great pleasure (7)
I believe the answer is:
delight
'great pleasure' is the definition.
(I've seen this before)
'day on lake in rowing boat' is the wordplay.
'day' becomes 'd' (abbreviation for day).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'lake' becomes 'L' (geographical abbreviation).
'in' means one lot of letters goes inside another.
'rowing boat' becomes 'eight' (I've seen this before).
'l' placed inside 'eight' is 'elight'.
'd'+'elight'='DELIGHT'
'gives' is the link.
(Other definitions for delight that I've seen before include "Gladden" , "Elation" , "Give great pleasure to" , "entrance?" , "Pleasure (possibly Turkish?)" .)