Portable plotter
Navigation app makes charting easy.
By Bob Mueller
Using NOAA charts and other proprietary chart formats, the iNavX Marine Navigation charting app allows users to create waypoints and routes as well as record tracks.
iNavX can be installed on the iPhone, iPad or iPod Touch. WiFi-only iPads and iPod Touches without internal GPS chips can run iNavX, but the position will not display on a chart; however, you can add third-party hardware to non-GPS iOS devices to display your position on a chart.
NOAA raster BSB charts, the primary charts used with iNavX, are free from the NOAA website. When the iOS device connects to the Internet, iNavX automatically goes to the NOAA website and downloads a chart for the current GPS position to keep charts up to date. If you’re using a device without 3G, you can download charts in advance using WiFi.
When first starting up, iNavX offers a menu showing U.S. regions that match up with the NOAA paper chart numbering system. Users have an option to “Add More Charts” available for purchase. Although relatively straightforward, the app’s user interface has a few frustrating eccentricities.
Choosing a NOAA region presents users with a menu of that region’s NOAA charts. Users can select charts by number or by entering a title in the search field. Points of interest or geographic features displayed on a raster chart are not searchable, however.
With raster charts, it’s critical to understand the difference between zooming and scaling. The standard iOS zoom technique will make the chart’s information larger or smaller. To change the amount of detail, you use plus and minus buttons to select a new chart in a different scale.
You can import and export waypoints easily with this app, but you need a paid X-Traverse account to fully use this function. Waypoints or routes cannot be imported by any other method.
Getting back to the chart screen from the app’s waypoints or routes functions can be confusing and awkward. Don’t hit the back button; instead, choose the “Chart” button at the bottom of the screen. Quite a few times I accidentally went back to the chart selection menu and had to reselect the chart with a few extra screen taps.
Despite a few user interface eccentricities, this app makes an excellent segue into electronic charting for navigators already comfortable with paper charts. The raster charts load and pan quickly. The course deviation indicator is useful when navigating a route. If the extra hardware is aboard, then having a portable and wireless display of the instruments is valuable. With this app, a skipper can allow a less experienced crew member time at the helm, while keeping an eye on information from the comfort of his bunk. Routes and waypoints can be exported and used with more robust marine GPS devices.
iNavX could be used as a standalone chart plotter, but it shouldn’t be the sole source of navigation in unfamiliar waters. It’s best used as a reference tool in familiar waters or as a backup to a more robust GPS chart plotter. Prudent mariners should always carry paper charts and a compass.
P/C Bob Mueller, JN, is an America’s Boating Course instructor, a vessel examiner and a Squadron Emergency Response Assistance Team leader. This article is a condensed version of one that originally ran on GPStracklog.com.
