Using your Seiko Astron GPS Solar watch is a breeze. Just expose it to light to keep it powered. You don't need to worry about changing the battery as it runs on light energy. Make sure to keep it away from strong magnetic fields as they can affect its accuracy. When it comes to maintenance, clean the watch regularly with a soft, dry cloth. If you want to clean the strap, use a mild soap and water solution and dry it thoroughly. Remember, this watch is water - resistant up to 100 meters, but avoid wearing it in hot tubs or saunas as the sudden temperature changes can damage it. Also, if you're swimming or diving, make sure all the buttons are properly locked to prevent water from getting in. With proper care, your Seiko Astron GPS Solar watch will serve you well for a long time.