Marine GPS: An Introduction
GPS navigators are perhaps even more useful at sea than on land. Marine GPS makes it possible to always return to an exact point on open water—a favored fishing spot for example. Plotting and staying on course are far simpler, even under difficult conditions. And in case of emergency, marine GPS provides the precise locational information rescuers most need to know.
The first decision you will face when shopping for a marine GPS navigator is whether you want a portable handheld device or a larger, fixed-mount chartplotter. If you know you want a GPS you can carry in your pocket, on the boat or off, then there’s nothing more to consider—you want a handheld unit. They’re just as accurate as larger navigators, and a lot less expensive.
Marine GPS Chartplotters
If you are outfitting your vessel for marine navigation, however, you probably want a wide screen GPS chartplotter. Chartplotters are marine GPS units with integrated navigational charts and other special features. At minimum a chartplotter displays basic navigational information such as the location, speed and heading of a ship. Many marine chartplotters also integrate and display information from sonar echolocators, radar and other sensors.
Marine chartplotters with built-in sounders can scan depths to 1000 feet or more, and provide topographic representation of the ocean bottom. Some GPS chartplotters have integrated fishfinders, to help locate and track schools of fish. Depending on your needs and the type of performance you want from your navigational system, you may also want to consider a marine chartplotter connected to a laptop computer for greater processing power.
GPS navigators and chartplotters provide information visually, and picture clarity may really suffer on a smaller screen. Reading a GPS screen in the glare of a sunny day on open water can be difficult, so look for a unit that has sunlight and nighttime viewing modes. Units with 5-inch to 10-inch screens are not just easier to use, they do a better job in getting you the information you want. Graphical data is far easier to see and interpret on a color screen than in gray-scale.
A growing number of widescreen marine chartplotters now have touch screen capability, which makes controlling the unit easy and intuitive. When it’s easier to control the device you’ll use it more, and explore more different features. For that reason alone, investing in a wide screen unit with touch screen control is a wise investment that will help you get more value from your marine GPS.
Fixed-mount marine GPS navigators don’t necessarily have to stay in your boat all the time. A number of great marine / automotive hybrid units are now available, loaded with charts and road maps and easily transferable from one setting to another. These can be a great solution if you are looking for GPS functionality on both land and sea.
Marine GPS Software
Most newer marine GPS systems come preloaded with navigational charts and data for U.S. waters. Garmin chartplotters, for example, come with preloaded “World Map” navigational charts. Additional Vision cards are available that offer expanded detail for specific areas. Newer units also come with extensive information on tides and currents, depth contours, marine services, points of interest and port plans, and other navigational aids. Some units like the new Garmin GPSMAP 640 can provide 3D ‘mariner’s eye view’ above the waterline and ‘fish eye view’ below the waterline. Others come with split screen capability, allowing you to view maps and weather data all in one screen.
There are a number of other features to consider when comparing marine GPS units. How easy is the device to install and remove? How easy is it to install additional software and navigational data? Does the processing power of the device provide for suitable rewrite speed when switching from one screen to another? How waterproof is the casing, and how resilient is the screen to heavy use in a marine environment? Finally, most GPS chartpoltters provide alarms to let you know when you have gone off course, or to alert you to changes in water depth or temperature. Be sure to check the alarm features on the marine GPS unit you are considering, keeping in mind what may be most useful to you or essential for safety.
Many new and used marine gps receivers and chartplotters can be purchased at discount prices through online auctions. Browse our store pages for Garmin GPSMAP Chartplotters, Lowrance Marine GPS, Humminbird Marine GPS, Raymarine GPS and more.