Call me crazy, but when I "Export Shaded Relief", the image is inverted. In other words, the troughs appear as peaks, and vice-versa. My data is gathered from a Lowrance machine, in their format. I don't see any way to "invert" the data. I must be missing something. Any ideas?

You are talking about the "relief inversion effect", which can affect any shaded relief map. It is really a matter of perception, since shading for a hill or valley is indistinguishable when viewed from above and how you see it depends entirely on which direction your subconscious perceives the light as coming from. The convention in GIS is to illuminate shaded relief maps from the NW, which is the default light angle for shaded relief maps in ReefMaster. If you have a hard time tricking yourself into viewing the relief the "right way" around, you could try changing the illumination angle (e.g. to come from the SE, which is the opposite of NW) - you can do this in the Shaded Relief map layer settings. This will cast shadows in the opposite direction, and might work better for you - although others might struggle if they are used to the NW convention. Visual perception of relief is quite an interesting topic in its own right - see also the Hollow Face Illusion.