The face of the depth dial says Tiefenmesser in that old-fashioned Gothic lettering that the Nazis loved so much. Messer means a gauge or meter, but it also means knife. Das Messer sitzt mir an der Kehle . The knife is at my throat; I am face-to-face with doom. When the knife is at your throat, you don’t want it to move the way the needle on the Tiefenmesser is moving now. Every tick on the dial’s face is another meter of water between Bischoff and the sun and the air.