Vessels caught on boulders (6)

I believe the answer is:

crocks

'vessels' is the definition.
(crock is a kind of vessel)

'caught on boulders' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'on' means one lot of letters go next to another.
'boulders' becomes 'rocks' (I've seen this before).
'c'+'rocks'='CROCKS'

(Another definition for crocks that I've seen is " Vessels".)

I've seen this clue in The Telegraph.

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