Vessel in water capsized (5)

I believe the answer is:

sloop

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

'vessel' is the definition.
(thesaurus)

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

(Other definitions for sloop that I've seen before include "'----- John B', 1966 Beach Boys' hit" , "One-masted sailing ship" , "Sailboat" , "Vessel with a single mast" , "Type of sailing boat" .)

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.