Using this Seiko Prospex Marinemaster watch is easy. Just wind it manually to start the automatic movement and set the time. The stop - second hand function can be used to accurately set the time. When wearing it, make sure the three - fold clasp is securely locked. For water activities, it can withstand up to 200m depth, but don't open the case underwater. To maintain it, keep it away from magnetic fields as they can affect the movement. Clean the watch regularly with a soft, dry cloth. If you notice any problems, take it to a professional Seiko service center.