The Navman F20 offers 2D- and 3D-map views, as well as day and night modes. In the 3D screen mode, the Navman F20 displays information such as: the current street and the name of the next street on your chosen route; direction and distance to the next turn; GPS status; a zoom button; and an information icon. When you press this button, the unit launches a page that displays the remaining distance to the destination, estimated time of arrival, the current time, your current speed, direction, and the unit's remaining battery life. The Navman F20 also can display text-based instructions, and has screens dedicated to showing the route's next turn and the route summary. Of course, all of this information is supplemented by voice prompts. The Navman F20 does not support text-to-speech functionality, however, so you'll only get generic instructions (for example, turn left in 100 feet) rather than specific street names.
The Navman F20 includes a comprehensive points-of-interest database that contains all the basics (gas stations, hotels, ATMs) as well as more specialized categories (amusement parks, concert halls, monuments). Some of the listings were out of date, however. For example, we searched for restaurants and bars in a San Francisco neighborhood, and discovered several listings had gone out of business.
We tested the Navman F20 in San Francisco. From a cold start, it took the unit about 3 minutes to acquire a GPS fix; subsequent starts were much faster. The Navman F20 accurately tracked our position as we drove around the city. We also entered a specific destination, and the Navman F20 quickly returned with a suggested route. We found the directions accurate, and the unit was quick to recalculate our route when we veered off track. That said, we had a hard time hearing the voice prompts, even with the volume up to its highest level. The F20 is rated for up to 3.5 hours of battery life.