Chapter 4 outlines how digital maps are valuable datasets to be explored for patterns and interrogated for clues as to how and why landscape features are arranged in space. Maps can inform scientific debate and management decision making. The spatial dimensions of a processes or feature of interest define the scope of a geographical area for spatial analysis. Historical maps made from a variety of field techniques represent baseline information against which coastal change can be assessed. Remote sensing represents a key contemporary source of spatial information derived from a sensor that is not in close proximity to the feature of interest. Optical remote sensing is commonly used to map shallow water coastal environments because light in the visible portion of the electromagnetic spectrum penetrates water. Remote sensing images need to be pre-processed to account for the effects of the atmosphere, water surface and water column before they can be interpreted to make coastal maps. LiDAR and sonar are forms of active remote sensing also applied in coastal environments to map water depths, which can also be estimated from satellite images and field data.