Carve sailboat, no end of oak being required (4)
I believe the answer is:
etch
'carve' is the definition.
(to etch is to carve into a material)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for etch that I've seen before include "Corrode" , "Engrave; fix firmly" , "Chase" , "Draw on metal with acid" , "Carve into metal with acid" .)