Qualifying race in the Atlantic (4)
I believe the answer is:
heat
'qualifying race' is the definition.
(I've seen this in another clue)
'in the atlantic' is the wordplay.
'in' says the answer is hidden in the clue.
'HEAT' can be found hidden inside 'the atlantic'.
(Other definitions for heat that I've seen before include "early round" , "Get agitated" , "Energy that causes a rise in temperature" , "Vehemence" , "Energy that caues a rise in temperature" .)