Step outside the pub to see the boat (7)
I believe the answer is:
pinnace
'the boat' is the definition.
(pinnace is a kind of boat)
'step outside the pub' is the wordplay.
'step' becomes 'pace' ('pace' can be a synonym of 'step').
'outside' is an insertion indicator.
'the pub' becomes 'inn' (I've seen this before).
'pace' going around 'inn' is 'PINNACE'.
'to see' is the link.
(Other definitions for pinnace that I've seen before include "Ship's boat - nice nap (anag)" , "tender" , "Vessel" , "Small boat" .)