Cold and unemotional type in charge, diver recalled (7)
I believe the answer is:
iceberg
'cold and unemotional type' is the definition.
'in charge diver recalled' is the wordplay.
'in charge' becomes 'ic'.
'diver' becomes 'grebe' (diving bird).
'recalled' shows that the letters should be reversed in order.
'grebe' back-to-front is 'eberg'.
'ic'+'eberg'='ICEBERG'
(Other definitions for iceberg that I've seen before include "A floating ice mountain" , "main danger" , "Unlikely feature of Cos" , "Maritime danger, mostly underwater" , "Largely hidden danger" .)