Lifesavers fail to get fevers on the boat, for instance (4)

I believe the answer is:

sail

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'boat for instance' is the definition.
'sail' can be an answer for 'boat' (sailing is a kind of boating). I am not certain of the 'for instance' bit.

I can't explain the rest of the clue.

Can you help me to learn more?

(Other definitions for sail that I've seen before include "Travel by ship" , "Go by water" , "Spanker or spinnaker, for example" , "Leave shore" , "Begin a voyage" .)

I've seen this clue in the Irish Times.

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