Underwater structure needs real force to break (5,4)

I believe the answer is:

coral reef

'underwater structure' is the definition.
(natural structure beneath the sea)

'real force to break' is the wordplay.
'to break' indicates anagramming the letters.
'real'+'force'='realforce'
'realforce' with letters rearranged gives 'CORAL-REEF'.

'needs' acts as a link.

(Another definition for coral reef that I've seen is " Navigational hazard in warm seas - real force (anag)".)

I've seen this clue in The Guardian.

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