GPS watches are simply watches that are capable of connecting to the GPS satellite network and using the signals recieved to calculate your precise location on the planet in three dimensions.

By measuring changes in location, speed, pace, distance travelled, altitude, vertical speed and facing can all be measured and displayed in real time, offering runners, cyclers, skiers and other athletes who participate in motion and endurance sports, features that until recently have been unheard of.

GPS watches are not just for athletes, many popular watches have in-built navigation and tracking abilities, so you can find your way to specifically marked points along your route, find out how far to your next waypoint and your ETA based on your current valocity. You can also backtrack to the beginning of your route, should you get lost.

GPS capable watches offer advantages to many kinds of sports. In this hub page, I will give an overview of the different types of GPS watches on the market, the main features and how they can benefit your sport as well as a comparisson of some of the more popular GPS watches currently on the market.

If you would like to learn much more about GPS sports watches, head over to my main sports watches site, where I present more information on GPS watches as well as the other leading sports watch manufacturers like Timex, Garmin, Suunto, Nike and Polar.

Photo courtesy of germanium.

GPS watches tend to come in two different varieties: One-piece and two-piece kits.

The single piece GPS watches like the Garmin Forerunner line, have the GPS aerial mounted in the wrist watch. A GPS aerial is generally quite large and so these types of watches tend to be quite large and chunky when worn on the wrist.

Two piece GPS watches like the Timex Bodylink, the Polar watches and the Suunto Training series watches require you to wear the GPS device externally from the wrist watch. Because the GPS aerial is mounted seperately from the wrist watch, the watch can be normal size, however you are required to attach a seperate piece of equipment to your body and wirelessly pair it with the wrist watch.

Consider which option you are more comfortable. One piece GPS units are starting to become smaller. For example the latest Garmin Forerunner 405 watch is a lot less bulkier than it's predecessor, the Forerunner 305. On the other hand, a two-piece GPS watch does not require you to wear the GPS pod, so you don't have to wear it every time.

Timex photo is courtesy of dionhinchcliffe.

One of the benefits of GPS watches that runners and cyclists enjoy the most is that these watches are capable of measuring speed, pace and distance travelled.

Most GPS watches can display your real-time statistucs upon a customizable screen. The Garmin Forerunner 405 for instance can display in excess of 30 fields of data, including three simultaneous screens on it's display. It can also be configured to cycle through a variety of customized screens on a timed basis, allowing you to view the full range of data fields that are on offer.

Most sports GPS watches can alert you based on upper and lower limits for speed, pace, distance and heart rate. This is an extremely useful feature for when you wish to follow a training program within certain parameters and guidelines, or if you are competing in an event and wish to know if you are on track to achieve your target time.

GPS watches are capable of measuring elevation above sea level, but this is less accurate than it's horizontal measurements. Never the less, if you are a hill runner, a climber or adventurer, a GPS watch can assist you with vertical features.

GPS watches are capable of measuring height above sea level, rate of ascent and descent and some can even alert you when you are above or below a certain altitude and measure your distance and time above an altitude.

If you want a higher level of vertical precision, look for a watch that has a barometric altitude feature, like the Suunto X10.

Most GPS watches facilite the transfer of data to PC and in some case Mac. Once the data is on your PC, the bundled software programs can import the data and in most cases display your courses on a map and is capable of doing a whole lot of other analysis of your workouts.

GPS watches like the Garmin Forerunner also have online communities that are compatible with the forerunner data, like MotionBased.com which is soon to become Garmin Connect.

There are also certain free third party software packages on the market that are capable of importing GPS data, so are well worth checking out. Such as SportTracks, which is a useful training log program in it's own right, even if you don't intend to import your GPS data.

Not all GPS watches have navigation features. The ones that do allow you to save your current location as a waypoint, the position is saved in the memory of your watch and can be navigated to in future.

GPS navigation watches allow you to record routes or record "breadcrumbs" which are points along the route you have taken. Later on, you can backtrack along your route back to your starting location. Many GPS watches like the Garmin 305 also present a 2 dimensional map, allowing you to visualise your position in 2D space.

Common navigation features, present on a GPS watch include:

• Compass feature
• 2 dimensional map view mode
• Save current location
• Delete a location from memory
• Navigate to a location in memory
• ETA to a waypoint based on current speed
• Auto-record a route travelled
• Delete a route from memory
• Activate a route in memory
• Back track to the starting location