Who could find water more delightful! (7)
I believe the answer is:
diviner
This clue is a double definition.
'who could find water' is the first definition.
(someone practising water divining)
'more delightful' is the second definition.
(divine can mean delightful)
(Other definitions for diviner that I've seen before include "even more delightful" , "More sacred" , "more godlike" , "one conjectures" , "A soothsayer" .)