The highest point left in a boat (8)
I believe the answer is:
pinnacle
This clue might be a double definition.
'the highest point' is the first definition.
(I've seen this before)
'left in a boat' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
Can you help me to learn more?
(Other definitions for pinnacle that I've seen before include "Acme" , "Height of success" , "The highest point, say of fame" , "Highest point (of fame or building)" , "The highest point, summit" .)