### Clue: Waters one teacher brought up with hot main (5,3)
### Answer: IRISH SEA 
 ### Explanation: Definition: Waters
 I(Roman numeral for "one") + **reversal of**(… brought up) SIR(a polite term of address for a male schoolteacher) **plus**(with) H(abbrev. for "hot") + SEA(the poetic term for which is "the main").**
Perhaps a reference to the movie dialogue:
Martins: Listen, Callahan!
Calloway: Calloway. I'm English, not Irish.