The most common and most likely answer to this crossword clue is the 8 letter word DIVINING
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More clues leading to the result DIVINING
Buddy explains!

The straight part
We know that "looking for water" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case looking for water = divining.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DIVINING mean?
DIVINING verb- To foretell (something), especially by the use of divination.
- To guess or discover (something) through intuition or insight.
- To search for (underground objects or water) using a divining rod.
- To render divine; to deify.
- The action of the verb to divine in any sense.
- That or who divines (in any sense of the verb).