Handing out qualifications

[Greystone]

I'm at the beginning of my career, end of 2nd patrol, and am beginning to hand out qualifications. A few questions..
If I wanted to improve hydrophone efficiency, would I give the "Radioman" qualification to a petty officer and stick him into the "Sonar" slot in the Sonar and Radio compartment?
On the bridge, I know that placing a petty officer, with a gunner or flak qualification in a deck gun/flak slot enhances gunnery efficiency, but would also giving the bridge lookout Officer a gunnery or flak qualification further enhance efficiency for one or the other?