In the wind at back of boat with clutch of eggs (5)
I believe the answer is:
afoot
'in the wind' is the definition.
(I've seen this before)
'at back of boat with clutch of eggs' is the wordplay.
'at back of boat' becomes 'aft' (aft means towards or at the end of a ship).
'with' means one lot of letters goes inside another.
'clutch of eggs' becomes 'oo' (visually resembles two eggs).
'aft' going around 'oo' is 'AFOOT'.
(Other definitions for afoot that I've seen before include "in the air" , "Progressing, in operation - like Sherlock Holmes's game" , "Astir" , "About to happen" , "Making progress" .)