Head of International Rescue's back (4)
I believe the answer is:
cape
'head' is the definition.
(both can mean a piece of land jutting over the sea)
'international rescue's back' is the wordplay.
'international' becomes 'cap' (sportsperson who competes internationally).
'back' indicates one should take the final letters (the letter at the back).
The last letter of 'rescue' is 'e'.
'cap'+'e'='CAPE'
'of' is the link.
(Other definitions for cape that I've seen before include "Notorious Chilean headland" , "Short sleeveless garment" , "An old cloak or a headland" , "Short cloak" , "Covering for the shoulders" .)