Tim Dodson asked about marking waypoints so this is one of the tricks I use when I see stuff like road beds, rock plies, old ramp or foundations. If you notice in the picture I just did a quick drawing of this area because I know there is an old boat ramp right next to this ramp. The red lines show were the ramp is. When I mark it, I will place dots or marks along the edge of it and the end of it to "draw" an outline. Then I will place one in the center with a title of what it is. Plus it helps with size reference. So if I find rock pile, I do the same thing. Outline with marks then one in the center. Now, you can easily see it on your map and know how to position your boat without having to scan it. Hope that helps explain it.