With the SD or microSD card formats, as mentioned, you may be able to update charts on your personal computer. It is important to have up-to-date charts, especially when sailing in unfamiliar waters. For instance, Garmin’s HomePort, Jeppesen’s PC-Planner, Raymarine’s Voyage Planner and Navico Insight Planner all allow you to transfer waypoints, tracks and routes between your home computer and chartplotter.
In many cases you can run standard SD or microSD cards on your home computer (PC or Mac) to update charts online and/or use them for planning and logging purposes. Older chartplotters used Compact Flash (CF) or proprietary cards (C-Card, Garmin). Be sure to check your chart region coverage, level of detail and data sources when purchasing.Īll current chartplotters use standard Secure Digital (SD) or micro-Secure Digital (microSD) data cards. If you are cruising in the Bahamas, you might be better off using electronic charts based on this data.
For example, the Explorer Bahamas charts, which claim to be the best source of local data, are licensed by Garmin and Jeppesen (but not by Navionics). Not every publisher uses the same underlying chart detail. Several publishers offer both “wide” and “local” coverage areas. Most chart publishers provide worldwide coverage for regions such as the East and West Coasts of the United States and Canada, unlike paper charts, where you typically purchase a few charts for your local sailing area. Most important is whether charts are available for your cruising area. Objects like navigational aids can also be queried for extra detail, and most chartplotters allow you to customize display colors, set safety-depth colors and contours, and display or hide objects by categories.īeyond that, there are several other questions to consider when selecting electronic charts. Note that as an added benefit, vector charts are “smarter” than rasters in the sense that depth soundings can be turned right side up even if you’re using the chart “head up” while going south. A vector chart can also look very precise when zoomed way in, but the user should understand that the detail is actually no more accurate than placing a magnifying glass on a paper chart. As a result, while a vector display can be less cluttered, you may have to zoom in quite far to see important details that are obvious on raster and paper charts. While raster charts will occasionally and noticeably change scale as you zoom in and out, vector chart objects can change every time they’re zoomed. They are typically smaller in file size, so that more regional coverage can be provided on a single chip. Since a human cartographer is not involved in creating the image, they often lack the nuance of paper charts and can look quite plain. Vector charts are databases of chart objects (soundings, shorelines, navigational aids, etc.) that are assembled into a screen image on the fly by the chartplotter. The traditional look and feel of raster charts may also reassure those easing into electronic charts. They are typically larger in file size and lack features like configurable depth units, on/off map information layers and other advanced functionality found in vector charts. Raster charts are scanned images of paper charts and are familiar to most everyone. In selecting electronic charts, you should decide whether you prefer raster or vector charts, or if you want to use both.
Several chart manufacturers reformat government electronic charts to work on their hardware, and numerous PC and tablet charting programs can display NOAA chart files directly. NOAA, for instance, offers more than 1,000 U.S. The hydrographic offices of several countries, like the National Oceanic Atmospheric Administration (NOAA) in the United States, share their data freely and also give away electronic versions of their paper charts.
It is important to understand that commercial chart suppliers usually license chart data from authorized government hydrographic offices that also produce paper charts.