The ABC’s Of GPS
Published: Friday, June 5, 2020
By: Dan Armitage
Global Positioning System (GPS) units are standard equipment aboard most recreational boats these days, especially those used on open water such as the Great Lakes. Developed by the military for navigation, the system relies on an elaborate network of satellites orbiting the Earth which can pinpoint the exact position and time of whomever is accessing their signals using a GPS receiver. As such, a marine GPS unit will enable you to determine your exact location and that of your destination, and direct you between the two; or more, you can use a marine GPS unit for "voyage planning," to plan your travel route among many ports even before your boat leaves the dock. It can also prevent you from getting lost on unfamiliar waters or in conditions with low visibility.
To use a modern, consumer-grade GPS unit, it’s fairly intuitive. You simply read the manual and learn what the signals on the GPS device mean, and program your unit for any journey you have planned. The user interfaces to do so are getting simpler all the time.
If you like to fish, most of today’s fish finders incorporate GPS functions with sonar to allow you to find fish or structures below the boat, mark the spot as a waypoint, and return at a later time. Some systems even “talk” to the boat’s engine or electric motor for sophisticated maneuvering using the signal from the GPS as a baseline. (See my article in the last issue on Yamaha’s XTO outboard and its state-of-the-art GPS linked capabilities.)
While most Great Lakes boaters use a fixed GPS receiver; either a stand-alone unit or one built into a fish-finder, GPS apps for use on smartphones are getting a lot of attention from boaters at present. BoatU.S. recently reviewed several of the most popular:
Navionics
Cost: App is free; $14.99 to download U.S. charts
I use and enjoy Navionics charts in my Humminbird GPS fish-finder combo and, based on that experience, will load this app when I launch this season. Probably the most popular navigation app, Navionics utilizes vector charts and allows the user to connect to some chartplotters via WiFi to transfer routes and waypoints. Charts, once downloaded, are stored on the device for offline use. Crosshairs allow for easy waypoint placement and access to local weather and tide information. Navionics offers a two-week free trial, after which the charts must be purchased to continue using the app. In-app purchases open up additional features such as auto routing and sonar charts.
Pros: Intuitive and easy to use; connects to some chartplotters; weather/tide info; free trial
Cons: Requires an annual subscription
That’s a Great (Big) Lake out there and a GPS unit will help you navigate it and more.
SeaNav
Cost: $19.95
SeaNav comes from the same company that bought out BoatBeacon, the well-known AIS app, and uses NOAA vector charts, which seamlessly download and link together as you scroll. The map interface offers chart, satellite, and hybrid modes. Further functionality is offered for those with Simrad, B&G, or Lowrance chartplotters through WiFi compatibility allowing sharing of data across the network. Considering the features offered, SeaNav appeals with great value for the money. Not sure if you want to pay yet? There's a free version that allows you to play with it, but you'll have to pay for specific charts.
Pros: Good value with easy-to-use interface; chartplotter compatibility; app for Apple Watch; includes 12 months of free updates for installed U.S. charts; free trial
Cons: iOS version only
iNavX
Cost: $4.99 (BoatUS Members receive a 10% discount on charts.)
The popular handheld chartplotter app works on both iOS and Android devices. There's a small charge to download the app, but then you can download NOAA raster charts for free. iNavX works with vector charts, too, including Navionics, Waterway Guides, NV Charts, and more, but there's an extra charge for these. For an additional cost, you can download and overlay Theyr and GRIB file weather data, a handy feature.
Pros: Superb navigation app; works with both raster and vector charts; weather data overlays available; 10% discount on charts for BoatUS Members
Cons: Takes some getting used to; some may find it overly complicated
Most of today’s fish-finders now include GPS chart-plotting capabilities.
iSail GPS
Cost: $7.99
This is an inexpensive option and there aren’t any signups, pop-up ads, or in-app purchases to spoil the experience. This isn’t the most comprehensive navigation app, but a solid, easy-to-use, no-frills navigation tool. Easily measure distance between two points of interest, and import and export waypoints, routes, and tracks. This app uses NOAA raster charts, and like many of the other apps, charts are stored on the device itself, not online, so the app is fully functional even when there is no WiFi or cell signal. One handy tool is the waypoint list that shows the ETA to each intermediate waypoint, not just to the final destination.
Pros: Cheap and cheerful; shows ETA to intermediate waypoints
Cons: Cheap and cheerful; iOS only
MX Mariner
Cost: $9.99
This Android-only app offers offline raster charts in addition to access to the Active Captain interactive guidebook. To add to functionality, the app also features road maps, but these are only available when the device is connected to cell or WiFi service. As with other apps, you can create, edit, input, and view waypoints and use the measure tool to quickly measure between two points on the chart. Distances can be displayed in nautical or statute miles or kilometers to suit the operator's preference.
Pros: Easy to use with no frills; road maps are useful for trailer boaters
Cons: Android only; road maps require access to network
Navigation by GPS continues to gain in popularity, access and ease of use. However, don’t forget the common compass for what remains the most reliable navigation tool aid on the water.
A GPS is worth its weight in walleye fillets when darkness falls or fog forms and you need to get back to the dock.
About the Author
Dan Armitage is a popular Great Lakes-based outdoor writer and host of the Buckeye Sportsman show (buckeyesportsman.net), syndicated weekly on 30 radio stations across Ohio. Dan is a certified Passport to Fishing instructor and leads kids fishing programs at Midwest boat and sport shows, and is a licensed Captain with a Master rating from the US Coast Guard.
This article first appeared in the Launch Issue (May/Jun) 2020 of Great Lakes Scuttlebutt magazine.
tags: Navigation, Software & Apps, Travel
