Forgive my nit-picky nerd rage, but...

The depth key for Figure 1C looks like it was hastily made, considering 2/5 of it is white. What color is 500M? White. What color is 1000M? Also white. 2500M? Still white! Is the Mid-Atlantic Ridge near the top of Figure 1C 2000M below sea level or 0M below? Considering the fact that the depth failsafe is 1400M (which is white!), one would think they'd have a more detailed depth key.