Wading bird, for instance, on back of boat (5)
I believe the answer is:
egret
'wading bird' is the definition.
(egret is a kind of wading bird)
'for instance on back of boat' is the wordplay.
'for instance' becomes 'eg' ('e.g.' can be a synonym of 'for instance').
'on' becomes 're' ('on' can be mean 'with reference to'**).
'back of' says to take the final letters.
The last letter of 'boat' is 't'.
'eg'+'re'+'t'='EGRET'
(Other definitions for egret that I've seen before include "(Usually) white heron" , "Long-plumed heron" , "Wader with white plumage" , "Bird eating fish" , "Water-bird, has plume" .)