Touch wrong handle on boat, some might say (9)
I believe the answer is:
scintilla
'touch' is the definition.
(both can mean a small amount)
'wrong handle on boat some might say' is the wordplay.
I cannot really understand how this works, but
'wrong' could be 'ill' (I've seen this in another clue) and 'ill' is found in the answer.
'some' could be 'a' and 'a' is present in the answer.
This explanation may well be incorrect...
(Other definitions for scintilla that I've seen before include "A tiny bit" , "The smallest amount" , "flash" , "Tiny trace or amount" , "little bit" .)