GPS Watches come in two different forms: those with an internally mounted aerial like the Garmin Forerunner watches and those connect to an external device worn on the body like the Polar RS800CX and Timex Bodylink watches.

The Garmin was the first popularize the concept of a self-contained GPS aerial with their original product line of Forerunner watches that included the 101, 201 and 301. (For a comparison see our Garmin Forerunner Comparison page).

The two GPS styles both have their pros and cons.

The upside of a self-contained aerial unit is that you do not have to worry about more than one device; you can just put your watch on and you’re ready to go.

The downside of the single piece unit is that it is a lot bulkier on the wrist than a normal sports watch. Garmin’s latest watch – the 405, however, is a lot less cumbersome than their legacy models.

A two-piece GPS unit is a device like Timex’s Navman sensors that comes with an arm band or belt clip and attaches to your body. While one may not wish to bother with strapping extraneous GPS sensor to your arm, for every “pro” there’s a “con”, and vice versa. The upshot of the separate GPS component is that the wrist-watch unit is much smaller than the Garmin, and actually looks like … well … a watch!

Battery Considerations

Another consideration you should take into account is the GPS battery life of your watch. Most two-piece GPS units require one or two AA or AAA batteries, whereas one-piece watches house a rechargeable lithium-ion battery, so there’s no need to go to the trouble and expense of purchasing new ones.

List of one-piece GPS watches

List of two-piece GPS watches

For more information on GPS sports watches, visit our GPS watches guide.