I did mean activities, I have put the required orientations in the manifest,
SetActivityAttribute(Audit_1, android:screenOrientation, "landscape")
SetActivityAttribute(Audit_2, android:screenOrientation, "portrait")
SetActivityAttribute(Audit_3, android:screenOrientation, "portrait")
Which works a charm. I just need to somehow temporarily lock the device to a particular orientation when the device is put in standby to stop users destroying the activity by changing the orientation. Does that make sense?