1. Introduction
This manual provides essential information and instructions for the proper use and maintenance of your Casio PRW6600Y Series Pro Trek watch. This timepiece is equipped with advanced features including Triple Sensor (Altimeter, Barometer, Thermometer, Digital Compass), Tough Solar power, and Atomic Timekeeping (Multi Band 6) for precise time synchronization. Please read this manual thoroughly to ensure optimal performance and longevity of your watch.

Image 1.1: Front view of the Casio PRW6600Y Pro Trek watch, showcasing its analog-digital display, multiple sensors, and robust design.
2. Safety Precautions
- Water Resistance: The watch is water resistant to 100 meters (330 feet). It is suitable for swimming and snorkeling but not for scuba diving. Do not operate buttons underwater.
- Temperature Extremes: Avoid exposing the watch to extreme temperatures, either hot or cold, for extended periods.
- Chemicals: Keep the watch away from gasoline, cleaning solvents, aerosol sprays, adhesives, paints, and other chemicals. They may cause discoloration, deterioration, or damage to the resin case and band.
- Impact: Avoid strong impacts or dropping the watch, as this may damage internal components.
3. Setup
3.1 Initial Charging (Tough Solar)
Your Casio PRW6600Y watch is powered by Tough Solar technology, which converts light into electrical energy. Before initial use, ensure the watch is fully charged by exposing it to bright light for several hours. The power indicator on the digital display will show the current charge level.
- Place the watch where its face is exposed to bright light.
- Avoid covering the watch face with clothing while wearing it, as this can prevent charging.
- The watch features a Power Saving Function that automatically enters a sleep state when left in the dark to conserve energy.
3.2 Time Setting (Atomic Timekeeping - Multi Band 6)
The watch automatically receives time calibration signals from six transmission stations around the world (Multi Band 6) to maintain accurate time. Manual time adjustment is generally not required if signal reception is successful.
- Home City Setting: Ensure your Home City is correctly set. In Timekeeping Mode, hold down the 'Adjust' button (usually top-left) until the city code flashes. Use the 'Forward' and 'Reverse' buttons (usually right side) to select your desired city.
- Manual Reception: To manually attempt signal reception, in Timekeeping Mode, hold down the 'Receive' button (usually bottom-right) for a few seconds. The watch will display 'RC!' indicating reception is in progress.
- Reception Status: Check the reception status (e.g., 'GET' for successful reception) to confirm the time has been synchronized.
3.3 Sensor Calibration
For accurate readings from the altimeter, barometer, and compass, occasional calibration may be necessary.
- Altimeter: Calibrate the altimeter by inputting a known altitude value (e.g., from a map or sign) when you are at that location.
- Digital Compass: Perform a bidirectional calibration to ensure accurate magnetic north readings. Follow the instructions in the full manual for the specific calibration procedure.
- Thermometer: For accurate temperature readings, remove the watch from your wrist for at least 20-30 minutes to allow it to acclimate to ambient air temperature, as body heat can affect readings.
4. Operating Modes and Functions
The watch features various modes accessible via the 'Mode' button (usually bottom-left). Pressing this button cycles through the modes.
4.1 Timekeeping Mode
This is the default mode, displaying the current time, date, and day of the week. The analog hands show the current time, while the digital display provides additional information.
- World Time: Access World Time mode to view the current time in various major cities around the globe.
4.2 Altimeter Mode
Measures and displays current altitude based on atmospheric pressure.
- Measurement Range: -700 to 10,000 meters (-2,300 to 32,800 feet).
- Memory: The watch can store manual memory measurements, including altitude, date, and time (up to 30 records).
4.3 Barometer/Thermometer Mode
Measures atmospheric pressure and temperature.
- Barometer: Displays atmospheric pressure, which can indicate weather trends.
- Thermometer: Displays temperature. Remember to remove the watch from your wrist for accurate ambient temperature readings.
4.4 Digital Compass Mode
Determines and displays magnetic north.
- Bearing Memory: Allows you to store a specific bearing for navigation.
- Ensure the watch is held level during measurement for accuracy.
4.5 Stopwatch Mode
Measures elapsed time.
- Measurement Unit: 1/100th of a second.
- Functions: Standard elapsed time, split times, and two finishes.
4.6 Countdown Timer Mode
Counts down from a specified time.
- Set a countdown start time, and an alarm will sound when the countdown reaches zero.
4.7 Alarm Mode
Set up to five daily alarms.
- Each alarm can be set for a specific time. An hourly time signal can also be activated.
4.8 Illumination
The watch features a Full Auto LED Light for illumination in low-light conditions.
- The light can be activated manually or set to turn on automatically when the watch is tilted towards your face in the dark.
5. Maintenance
5.1 Cleaning
- Wipe the watch with a soft, dry cloth to remove dirt and moisture.
- For resin bands, wash with water and a mild detergent, then rinse thoroughly and dry.
- Avoid using harsh chemicals or abrasive cleaners.
5.2 Water Resistance
While the watch is water resistant to 100 meters, proper care is essential:
- Do not operate buttons or the crown while the watch is wet or submerged.
- After exposure to saltwater, rinse the watch with fresh water and wipe it dry.
- Avoid exposing the watch to high-pressure water streams.
5.3 Battery (Tough Solar)
The Tough Solar power system eliminates the need for regular battery replacement. However, ensure the watch receives sufficient light exposure to maintain a full charge.
- If the watch's charge level drops too low, some functions may be disabled.
- The Power Saving Function helps extend battery life by entering a sleep mode when the watch is in darkness.

Image 5.1: The Casio PRW6600Y Pro Trek watch worn on a wrist, demonstrating its size and fit.
6. Troubleshooting
- Incorrect Time: Ensure your Home City setting is correct and that the watch is receiving time calibration signals. Place the watch near a window overnight for better reception.
- Sensor Readings Inaccurate: Calibrate the altimeter, barometer, and compass as described in Section 3.3. Ensure the watch is level for compass readings and off the wrist for temperature readings.
- Watch Not Charging: Ensure the watch face is exposed to bright light. Check the power indicator. If the charge level is low, expose it to direct sunlight for several hours.
- Buttons Not Responding: If the watch has been exposed to water, ensure it is completely dry before operating buttons. If the issue persists, a reset may be required (refer to the full Casio module manual for specific reset procedures).
7. Specifications
| Feature | Specification |
|---|---|
| Model Number | PRW-6600Y-1A9CR |
| Water Resistance | 100 meters (330 feet) |
| Power Source | Tough Solar (Solar Powered) |
| Timekeeping | Atomic Timekeeping (Multi Band 6) |
| Sensors | Triple Sensor (Digital Compass, Altimeter, Barometer, Thermometer) |
| Altimeter Range | -700 to 10,000 meters |
| Stopwatch | 1/100th second, up to 24 hours |
| Countdown Timer | Yes |
| Alarms | 5 Daily Alarms, Hourly Time Signal |
| Illumination | Full Auto LED Light |
| Case Diameter | 51.5mm |
| Band Material | Silicone |
| Product Dimensions | 6 x 6 x 4 inches; 8.15 ounces |
8. Warranty and Support
Your Casio PRW6600Y Series Pro Trek watch is covered by a manufacturer's warranty. For detailed information regarding warranty terms, service, and support, please refer to the warranty card included with your product or visit the official Casio website. Keep your proof of purchase for warranty claims.

Image 8.1: The packaging box for the Casio Pro Trek watch, featuring the brand logo and design.





