If you are thinking about buying a new GPS for your boat and are unsure how it functions or how to even use it, no problem. These units built nowadays are easy to operate.

Where do We Begin What is a GPS? GPS stands for Global Positioning System. Made for the military, a GPS can function anyplace in the world. It makes use of satellites in space to give you the latitude and longitude for your exact position on the land or water. There are a lot of makes on the retail market; Garmin, Raymarine, Furuno to name a few. They all do the same thing, but several have added features. It's all related to your individual preferences. If the GPS has a built-in antenna, it is ready to run after you hook up the power connections. You must have a clear view of the sky as a boat hardtop will prevent the GPS from receiving satellite signals. If your GPS has a remote antenna, put the antennae on the hardtop, radar arch or rail. Since a GPS antenna is "looking" up, there is no benefit to mounting it high. In fact, putting it high can trigger course and speed variations because of the yacht rolling.

First Startup Once you run your GPS receiver, it will start to receive signals from all satellites in its view. It will need a couple minutes to recognize and lock on to the satellites that will provide the top fix for its position. If you are turning the machine on for the first time, or if it has been relocated a good distance since it was last operating, it could take a little longer than normal as the GPS will need to "discover" its position. The GPS receiver will lock on to a minimum of 3 satellites to triangulate its position. Many GPS monitors will show some type of status screen while the receiver is collecting information from the satellites. Some GPS devices even provide you with the satellite position. When the GPS locks on to the satellites, it will automatically indicate the latitude and longitude for your present position. If you have purchased a chartplotter GPS, it will also place your location on the graphic chart. Bear in mind however, that electronic charts are designed to be an aid to navigation and not take the place of NOAA paper charts. As your trawler moves, the GPS will routinely update you with your present location as well as moving your yacht on the chart.

Waypoints If you wish to mark your location for future navigation, you are able to have the GPS save your present location. We identify those as waypoints. By storing waypoints you are able to return to that magnificent fishing ridge offshore any time in the future. The process for saving is distinct for every GPS, but saving a waypoint is as straightforward as pressing the WAYPOINT button on the receiver. Let's go on a hypothetical voyage to see how this works. Subsequent to powering up our GPS, we leave to do some offshore fishing. As we go by #5 buoy on the way out of the inlet, we press WAYPOINT to remember as our initial position. The GPS gives the waypoint a numerical description-001. We travel offshore to the coordinates of a reported sunken vessel where we plan to discover some grouper. When we find the ship by means of our fish finder, we again depress the WAYPOINT button to remember that spot. The GPS assigns the numeral 002 to that place. Now, subsequent to a good day of fishing when we are all set to go home, we depress the GOTO button on the GPS and it displays a list of waypoints. We select 001, and the monitor shows us the route (bearing) and distance to this starting waypoint on our route. As we travel in the direction of that waypoint, the GPS continually updates the bearing and distance, and shows what course changes are needed to compensate for current or steering. Next week when we want to go back to the submerged boat, all we will have to do is select waypoint 002 and we will be routed back to it. You are able to also input a waypoint by entering the coordinates directly into the receiver. The GPS will designate a number to it and you are able to direct the GPS to go to that position.

Precision of the GPS The accuracy of a GPS fix is usually within one hundred meters. That is sufficient to get you to that sunken boat, but it isn't sufficient to attempt navigating a narrow channel in thick fog. Here is where differential GPS plays a role. Differential GPS utilizes a land-based receiver to calculate the standard GPS miscalculation and transmits corrections to your differential GPS-outfitted receiver. A differential GPS-equipped receiver has a precision of around 10 meters-thirty feet. Bear in mind, the military has control over the satellite signals and differential transmission, and in time of a national crisis may switch them off. Turning the unit on and getting a fix is simple. Saving waypoints while you are cruising is also simple. By utilizing your GPS and tinkering with it, you will soon grasp all of the features that will make your cruising enjoyable and safe. Have fun on the water.