Where ratings are lost (2,3)
I believe the answer is:
at sea
I believe this is a double definition.
'where ratings are' is the first definition.
(rating can mean a sailor)
'lost' is the second definition.
(both can mean confused or in trouble)
(Other definitions for at sea that I've seen before include "Where to find flounders" , "All bothered and bewildered" , "Where a packet might be" , "disorientated" , "On a moving ship?" .)