Is safety shading a standard feature, or does it require a vision card? I don't have a vision card, but at one time on my navigation screen, i saw areas of blue that indicated shallower water. I can't get that back and almost went aground this past weekend. I did a factory reset, and Safety Shading doesn't ever show up in the menu.
Bottom-line, I had that or a similar feature at one time, and now I've lost it. What am I doing wrong? Zoom level? A setting?