Your first cobbler's tool in sailing boat? (4)
I believe the answer is:
yawl
'sailing boat?' is the definition.
(I've seen this before)
'your first cobbler's tool' is the wordplay.
'your first' becomes 'y' (1st letter of 'your').
'cobbler's tool' becomes 'awl' (I've seen this in another clue).
'y'+'awl'='YAWL'
'in' is the link.
(Other definitions for yawl that I've seen before include "A two-master" , "Two-masted sailing vessel" , "Two-masted sailing boat" , "Ships small boat" , "Sailing vessel with two masts" .)