Divers in SOS: aides probing subject of inquiry – this? (7,7)

'inquiry this?' is the definition.
The definition suggests a singular noun which matches the answer.

'divers in sos aides probing subject' is the wordplay.
I cannot quite see how this works, but
an anagram of 'sos' is 'sso' which is present in the answer.
'in' is within the answer.
an anagram of 'aides' is 'adise' which is present in the left over letters.
'subject' could be 'case' (case is a kind of subject) and 'case' is found within the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...

'of' is the link.

Can you help me to learn more?