Choosing your cartography

Before selecting a card reader, it is necessary to choose its cartography. Each device operates with a unique brand chart. You can explore the characteristics of each of three brands of charts available today in our, “cartography,” dossier. Note that with the exception of Garmin, which has cartography useable only on its own brand’s devices, Navionics and C-Map charts may be read by different brands of readers. There i  though, no universal reader. A reader designed to read Navionics charts cannot read C-Map charts and vice versa.

Screen size

The quality of a reader is, above all, that of its screen. Larger versions are better, as the surface of the chart is more easily readable. A small screen requires constant zooming, forward and back. Forward to view the route then reversing to plot the boats course on the water. For reading fixed charts, a screen of 7 inches diagonally (18cm,) seems to be the minimum for comfortable reading. When choosing a small screen, one must ensure that the power of the apparatus (the microprocessor,) is fast enough to support the display of multiple zooms.



Touch screen or keyboard?

The touch is more fashionable, but is it practical for navigation? Indeed, at sea, with the movements of the boat, it is not always easy to place fingers on the screen accurately. If selecting an option menu is not too difficult, placing a waypoint precisely may be. Garmin, whose expertise comes from the automotive world, has made the choice of all touch, with menus specifically contained. Others, such as Raymarine or Simrad, have chosen to produce mixed devices, touch, but with a keyboard, for easier handling at sea. Finally, there are those with only a keyboard.

Readable in direct sunlight

Using a card reader may be easier if the unit is installed, often externally, near the helm (on the console of an open shell, or the cockpit of a sailboat.) We must therefore choose a device that is waterproof, or at least its face (they all are) and that above all, with a screen readable in direct sunlight. The new backlit TFT screens possess this property.


Professional advice

“Touch screens do not function if one is wearing gloves but remainusable in rain. They use sensitive technology.”