Using your G-Shock GA-010 watch is a breeze. To check the world time or use the stopwatch, just press the relevant buttons on the side of the watch. For the high - brightness LED light, press the large button on the front of the case. When it comes to water resistance, you can wear it while swimming or snorkeling up to 200 meters deep, but avoid pressing buttons underwater. To maintain your watch, clean it regularly with a soft, dry cloth. Since it has a 10 - year battery, you don't need to worry about battery changes often. However, if you notice the watch is not functioning properly after 10 years, it's time to replace the CR2025 battery. Keep it away from extreme temperatures and strong magnetic fields to ensure its long - term performance.