Know-all I found on ocean in ragtag crew (8)

I believe the answer is:

wiseacre

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'know-all' is the definition.
(I've seen this before)

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

(Other definitions for wiseacre that I've seen before include "One assuming air of superior wisdom - simpleton" , "Show-off" , "Smart alec" , "Person who tries to appear clever" , "Know-all" .)

I've seen this clue in The Guardian.

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