Marine GPS: Take to the Open Waters

Marine GPS navigation requires knowledge above and beyond land navigation. Rocks, shallow water, and wrecks are common obstacles, and since fog often occurs on coastal waters, it's critical to know where you are. Recreational boaters usually stick close to land and this may seem to be a clear advantage, but that is where the majority of hazards are. GPS gives your location, but you need additional information: charts.

Chartplotters are a big improvement over handhelds. They display the GPS information overlaid on the nautical charts. While not a complete replacement for paper charts, the chartplotter will be the primary navigation tool. The screens are larger, there are usually more buttons, and the buttons are larger. They are meant to be mounted to a fixed surface, and they usually have external antennas, so placement is not an issue. Chartplotters start at about $400 US and screen sizes vary from about 5 - 10 inches. You will pay a little more for a color screen, but the extra cost is worth being able to discern important features. Many chartplotters are integrated, which means that the GPS receiver and the chartplotter are one unit. If you have a bigger boat and a bigger budget, chartplotters are available that do not have the GPS integrated within. These usually have larger and better screens. By using the chartplotter to display data from other devices such as radar, depth sounder, etc., the extra cost is justified.