If you’ve fished as long as I have you remember using paper charts that you had to roll-up to put away. They were accurately detailed and were color codes for depths. For those of us that enjoyed using those charts, C-Map 4D offers Raster Charts as part of their selection that works with Raymarine fishfinders.
With raster charts, you have an additional reference source for navigational awareness. It provides you “at-a-glance” information using the nautical paper charts overlaid on the multi-dimensional shaded relief to have a new visual experience.