At sea, green sand puts another at risk (9)

I believe the answer is:

endangers

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

'puts another at risk' is the definition.
I can't judge whether this defines the answer.

'at sea green sand' is the wordplay.
'at sea' indicates an anagram.
'green'+'sand'='greensand'
'greensand' is an anagram of 'ENDANGERS'.

Can you help me to learn more?

(Other definitions for endangers that I've seen before include "poses a threat" , "Risks" , "Places in peril" , "Imperils" , "Puts in peril" .)

I've seen this clue in the Sydney Morning Herald.

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