Disasters involving upper-class holidays at sea (7)

I believe the answer is:

cruises

'holidays at sea' is the definition.

'disasters involving upper-class' is the wordplay.
'disasters' becomes 'crises'.
'involving' is an insertion indicator.
'upper-class' becomes 'u' ('u' can be similar in meaning to 'upper-class').
'crises' placed around 'u' is 'CRUISES'.

(Another definition for cruises that I've seen is " Holidays on water".)

I've seen this clue in The Telegraph.

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