Even worse, Cobra claims that the GPS 500 is designed to withstand submersion in water to IPX7 standards (1 meter for 30 minutes), but the device literally went belly up, showing noticeable seepage in the screen and the battery compartments after we soaked it for just 15 minutes. The unit was inoperable thereafter. On the plus side, the GPS 500 floated as advertised. The Cobra GPS 500 receiver is unique in that it employs 18 channels to search for satellite signals, whereas other products go with 12-channel technology. The device is WAAS (Wide Area Augmentation System) enabled and uses Cobra's ASAP (Accelerated Satellite Acquisition Protocol) technology. According to the company, this enables satellite locking in half the time of other GPS systems, but our performance tests said otherwise. The device is preprogrammed with a base map of U.S. state boundaries and worldwide city coordinates, along with Canadian and European country boundaries, but the system doesn't include highway and street-level data.
The 2MB of nonupgradable internal memory is insufficient for loading street-level maps, but it's adequate for storing waypoints and track logs. This bit of memory can also handle POI (points of interest) data downloaded via the optional Rand McNally StreetFinder software ($99.95). In addition, the GPS 500 lets you store up to 500 waypoints and save as many as 10 tracks, and it has a built-in altimeter, compass, and clock. By scrolling through the menus, you can view current and average speed, trip time, odometer, elevation, and ETA to a predetermined location. The GPS 100 shares these last set of features but lacks the extra memory and the PC compatibility that its higher-end sibling boasts. For all of its exclusive receiver technology, the Cobra GPS 500 turned in less than stellar performance results in our tests. Upon initial start-up, the device took 3.5 minutes to acquire a 3D (four satellites) fix under a clear sky with an unobstructed view. Down at the beach, we tried again and had to wait more than 5 minutes before we saw results. Predictably, the unit had trouble finding and holding a strong signal while driving (the Cobra was mounted on the dashboard with a clear sky view), and we were constantly reminded of this by the beeping alarm. The device fared no better when we were walking the streets of Manhattan. On the other hand, when it managed to maintain a 3D fix, it was extremely accurate in tracking our position and guiding us to our stored waypoints.
Battery tests proved more hopeful. Powered by two AA batteries (not included), the GPS 500 is rated for 10 to 12 hours of continuous use; we were able to squeeze out nearly 11 hours before the unit shut down.