Helpful words coming out of rescue ships (4)
I believe the answer is:
cues
'helpful words' is the definition.
'coming out of rescue ships' is the wordplay.
'coming out of' indicates the answer is hidden within the clue.
'CUES' is hidden in the letters of 'rescue ships'.
(Other definitions for cues that I've seen before include "Prompts for action" , "Actors' signals" , "Snooker ball strikers" , "Snooker rods" , "Signals for action" .)