Dangerous removing gear in stretch of water (5)

I believe the answer is:

sound

I'm a little stuck... Click here to teach me more about this clue!

'stretch of water' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for sound that I've seen before include "Fit" , "Speaking" , "Fathom" , "strait" , "Financially stable" .)

I've seen this clue in the Irish Times and the Irish Times (Crosaire).

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