Reasons he emptied equipment - to find waterproof cover (11)
I believe the answer is:
groundsheet
'waterproof cover' is the definition.
'groundsheet' can be an answer for 'cover' (I have seen 'protective cover' mean 'groundsheet' so perhaps 'cover' could also mean 'groundsheet'). I am not sure about the 'waterproof' bit.
'reasons he emptied equipment' is the wordplay.
'reasons' becomes 'grounds' (grounds or reasons for an action).
'emptied' says to hollow out the word (remove centre letters).
'equipment' with its centre taken out is 'et'.
'grounds'+'he'+'et'='GROUNDSHEET'
'to find' is the link.
Can you help me to learn more?
(Other definitions for groundsheet that I've seen before include "something for campers" , "campers need it" , "Waterproof base for tent" , "Camper's protection from damp" , "protective cover" .)