Here is another example of a dive Instructor using the Z Gear BCD mount (with the extension kit). In this footage he is watching as students perform the emergency accent drill. The extension on the mount allows you to watch you are filming and you can adjust the angle when desired.
https://www.youtube.com/watch?v=6rEE4fbyzAI
https://www.youtube.com/watch?v=YjlrJK_XfO0
https://www.youtube.com/watch?v=6rEE4fbyzAI
https://www.youtube.com/watch?v=YjlrJK_XfO0