The most common and most likely answer to this crossword clue is the 6 letter word BATHER
I've seen this crossword clue in The Daily Telegraph
B
A
T
H
E
R
More clues leading to the result BATHER
- Club attracts female swimmer
- Almost crazy, that female swimmer
- Club joined by the female swimmer?
- Pub welcomes the one who washes
- Inside pub is the man who gets soaked?
- Sailor returns with the river swimmer perhaps
- Article in tavern for someone in a tub
- Sailor turned up on the river, finding one taking a dip
Buddy explains!

The straight part
We know that "one taking a dip" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one taking a dip = bather.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 BATHER mean?
BATHER noun- One who bathes or swims.
- One who gives a bath to another.