### Clue: Divers use it in worst extremes (3,4)
### Answer: WET SUIT 
 ### Explanation: Definition: Divers use it
 **Anagram of**(Divers;varied) USE IT **contained in**(in) **the 2 outermost letters of**(extremes) "worst ".
Answer: The "it" in the defn. A WIWD(wordplay intertwined with defn.) clue.