Using your Seiko Prospex Marinemaster Automatic Watch is easy. You can wind it manually or let it wind automatically as you move. The watch has a power reserve of about 45 hours, so you don't have to worry about it stopping quickly. When wearing it, the flexible double - curved bracelet will fit comfortably on your wrist. For water - related activities, it can resist water up to 200 meters, but avoid sudden temperature changes when it's wet. To keep it in good condition, clean the bracelet regularly with a soft cloth. You can also have it serviced by a professional every few years to ensure its long - term performance.