Despite the fact that the LCD is very clear and bright, it is the GPS receiver which consumes most of the power. Silva has taken a minimalist approach to designing the keypad which has a choice of only seven large, friendly buttons to press. The operation of the compass is menu driven with four of the buttons assigned to scrolling through the menu options and the fifth 'key' used to lock and unlock the commands and waypoints for adjustment and setting. The arrow keys are also used to scroll through numbers and letters when entering waypoints directly. While this design is very pleasing to the eye it does make operating the compass slightly tiresome and relatively difficult to do freely without a reasonable degree of familiarity with the menu layout.
Familiarity comes quickly, fortunately, with a couple of days of practise.
In the unit we were provided, the batteries were exhausted very quickly in continuous navigation mode, lasting only a few hours. Silva claim that the latest model sustains much longer use - up to twelve hours. When not in continuous navigation mode a single position fix takes about one minute, though the first fix in a new region will take longer, as will fixes performed when reception is poor, such as in bad weather or in forests. The Silva GPS compass will be useful to professional geologists working in areas where base maps are relatively poor or where the safety of the working group is paramount. One purchased for such a purpose, however, is likely to find itself employed at the weekends by those professional geologists who enjoy hill walking, yachting or rallying.