Pull fish over towards the sheltered side (7)
I believe the answer is:
leeward
'towards the sheltered side' is the definition.
(I've seen this before)
'pull fish over' is the wordplay.
'pull' becomes 'draw' (synonyms).
'fish' becomes 'eel' (eel is a type of fish).
'over' shows that the letters should be reversed in order.
'draw'+'eel'='draweel'
'draweel' written backwards gives 'LEEWARD'.
(Other definitions for leeward that I've seen before include "The way the wind blows" , "Quarter towards which the wind blows" , "Drew ale (anag.)" , "Of ship, on side turned away from wind" , "Heading for shelter" .)