Garmin is known for making some of the most user friendly GPS Handheld and GPS Plotter systems on the market, but you still need to know a little about map reading and navigation to get the most out of your Garmin GPS.  Whether you have chosen a basic system that simply gives you your geographic coordinates, or a top of the range version which actually plots your position on a digital map, it is still useful to know a little bit about how to find your way around the system in order to use it to navigate efficiently, and get to your destination as safely as possible.

When you are on land, getting around is simple thanks to all the convenient landmarks, and street names that show you where you are, and thanks also to the road signs which point you in the right direction.  At sea, or in wilderness areas, you will find that Garmin GPS systems really come into their own, although, it is one thing to know where you are, and another thing entirely to find out where you are going.

Global Positioning Systems or GPS like Garmin rely on tracking the signal from satellites orbiting high above the earth’s surface.  The satellites orbit in a fixed position relative to the earth and each other, and transmit a constant signal.  Your Gamin GPS picks up the signal from all the satellites that are visible to it above the horizon, and by comparing the relative strengths of these radio signals is able to calculate its exact position to a high degree of accuracy.

Your position is given as two separate numbers called co-ordinates.  The first one of these is known as the Latitude figure.  This refers to how far north or south of the equator you are, while the second figure or Longitude tells you how far east or west of an invisible line through London, England you are.  A negative latitude number means that you are south of the equator, while a negative longitude number means that you are west of London.

All standard maps and charts use the same figures for latitude and longitude, which means that as long as you have the appropriate map to your location, you can find out where you are by knowing the coordinates of your position.  In the past, sailors used a selection of instruments including chronometers and sextants to determine their position, and it was important to do this regularly in order to navigate properly, while now all you need do is press a button to call up the location via your Garmin GPS, and then track it on whatever kind of map you are using.

If you have a Garmin GPS with an inbuilt map, then it will show you your location relative to the various landmarks or land masses around where you are, as well as providing information about currents and sea profiles if you are at sea.  If on the other hand, you are combining the use of your GPS with a traditional map, you will need to plot your position by measuring along the axes of the map, to find your longitude and latitude.

A good quality electronic satellite navigation device will keep a track of your movements for a predetermined amount of time, allowing you to see where you have been and measure your progress along the route you are following, but if you are using a map, you need to draw the line and measure it using a pair of protractors to keep an eye on your speed at sea.

It is important to keep regular checks on position, especially if you are traveling through shallow waters.  This will prevent you from running aground, which can be dangerous and costly if you do damage to your boat.

The most important thing to remember when using a Garmin GPS system for navigation is that it is not an alternative to common sense and care; it is a tool to make things simpler.  You should still behave in a manner that is respectful to the sea, and keep track of your position.  While Garmin GPS are amongst the most reliable navigation tools currently available, they are not infallible, and you should always use them in conjunction with your intelligence.