Point small boat across loch (8)
I believe the answer is:
pinnacle
'point' is the definition.
(pinnacle is a kind of point)
'small boat across loch' is the wordplay.
'small boat' becomes 'pinnace' (I've seen this before).
'across' means one lot of letters goes inside another.
'loch' becomes 'l'.
'pinnace' going around 'l' is 'PINNACLE'.
(Other definitions for pinnacle that I've seen before include "Culmination" , "Apogee" , "The highest point, summit" , "The highest level" , "Topmost point" .)