Ruined steamer owner's getting high in seaside town (6-5-4)

I believe the answer is:

weston-super-mare

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'town' is the definition.
(I've seen this before)

'ruined steamer owner's getting high in seaside' is the wordplay.
I cannot quite see how this works, but
'high' could be 'up' (associated in meaning) and 'up' is located in the answer.
This explanation may well be incorrect...

Can you help me to learn more?

I've seen this clue in The Guardian.

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