Important subtle point for those reading along who are a little uncertain about their compass work:
Note in Marie's photo where the window lies. It's NOT where the standard pics of using a wrist mounted compass would suggest, with your arm at right angles to your direction of travel.
With the window in line with her arm, she can navigate with her arm fully extended, getting the advantage of a slate-mounted or console-mounted compass being extended far in front of you. This is one advantage of a bungee: you can mount 90 degrees out of the alignment that would obtain if you used the wrist straps. But with wrist straps you are looking down at your compass, and it is very close to your body (and other possibly ferromagnetic material, like your steel tank). Also, it is less stable as you look down to check heading, look up to check direction, look down to check heading, etc., etc. Extending it away from you is the way to go for accuracy.
That means a slate, a console, or @Marie13 's nice bungee arrangement for an extended arm! Very cool!
