Sorry, I should have used proper period terminology.
From reading too many Tom Clancy books I'm used to calling both active and passive gear SONAR.
In WW2 only the active gear was called SONAR.
The passive was generally called hydrophone.
In SH3 the qualification is actually called 'Radioman' (I think).
This applies to any gear that is used in that compartment - be it the radio, hydrophones or sonar (when you get one).Give your guy the Radioman qualification, then you can stick him on the radio, or on the hydrophone/sonar gear.
I hope that's a bit clearer
