1. Product Overview
This manual provides instructions for the Nautica One Men's Watch, model NAPNOS306. This timepiece features a robust design with chronograph functionality and water resistance suitable for various activities.
Key Features:
- Case: Silver-tone 48mm recycled (85%) stainless steel case with mineral glass crystal.
- Dial: Black dial with chronograph movement and date display at the 4 o'clock position.
- Hands: Luminous infill on hands for improved visibility in low light conditions.
- Straps: Includes an adjustable recycled (85%) stainless steel bracelet and a 22x22mm black silicone strap.
- Water Resistance: Water-resistant up to 100 meters (330 feet).
- Crown: Screw-down crown for enhanced water resistance.
- Case Back: Screw-down case back.

Image 1.1: Front view of the Nautica One Men's Watch with stainless steel bracelet.
2. Setup and Initial Adjustment
2.1 Setting Time and Date
- Unscrew the Crown: Gently unscrew the crown (located on the right side of the watch case) counter-clockwise until it is free from the case.
- Pull to Position 2 (Date Setting): Pull the crown out to the first click position. Turn the crown clockwise or counter-clockwise to set the date. Avoid setting the date between 9 PM and 3 AM to prevent damage to the movement.
- Pull to Position 3 (Time Setting): Pull the crown out to the second click position. Turn the crown to set the hour and minute hands. To ensure accurate time setting, synchronize with a reliable time source.
- Push and Screw Down the Crown: Once the time and date are set, push the crown back into the first click position, then gently push it all the way in and screw it clockwise until it is securely tightened against the case. This ensures water resistance.

Image 2.1: Side view illustrating the crown and chronograph pushers.
2.2 Adjusting the Bracelet / Changing Straps
The watch comes with both a stainless steel bracelet and a silicone strap. The stainless steel bracelet can be adjusted by removing or adding links. It is recommended to have this done by a professional watchmaker to avoid damage.
To change between the stainless steel bracelet and the silicone strap, use the provided spring bar tool. Carefully depress the spring bars located on the underside of the strap where it connects to the watch lugs. Remove the current strap and attach the desired one by aligning the spring bars with the lug holes and releasing them. Ensure both ends of the strap are securely fastened before wearing.

Image 2.2: Watch kit showing the stainless steel bracelet, silicone strap, and strap changing tool.
3. Operating the Chronograph Function
The Nautica One watch features a chronograph (stopwatch) function. The chronograph is operated using the two pushers located on either side of the crown.
- Start/Stop: Press the top pusher to start the chronograph. Press it again to stop the timing.
- Reset: After stopping the chronograph, press the bottom pusher to reset all chronograph hands to their zero positions.
The sub-dials on the watch face display the elapsed seconds, minutes, and 24-hour time for the chronograph function.
3.1 Water Resistance Guidelines
This watch is water-resistant to 100 meters (330 feet). This rating makes it suitable for swimming, snorkeling, and recreational diving.
- Important: Ensure the crown is fully screwed down before any contact with water to maintain water resistance.
- Do not operate the crown or pushers while the watch is submerged in water.
- Avoid exposing the watch to extreme temperature changes (e.g., hot showers followed by cold water) as this can compromise seals.
- After exposure to saltwater, rinse the watch with fresh water and dry it thoroughly.
4. Care and Maintenance
4.1 Cleaning
Regular cleaning helps maintain the appearance and longevity of your watch.
- Wipe the watch case and crystal with a soft, dry cloth.
- For the stainless steel bracelet, use a soft brush and mild soapy water to clean between the links. Rinse thoroughly with fresh water and dry immediately.
- For the silicone strap, wash with mild soap and water, then rinse and dry.
- Avoid using harsh chemicals, solvents, or abrasive cleaners.
4.2 Battery Replacement
The watch is powered by a quartz movement requiring a battery. When the battery needs replacement, it is recommended to take the watch to an authorized service center or a qualified watchmaker. This ensures proper battery installation and re-sealing of the case back to maintain water resistance.

Image 4.1: Rear view of the watch, highlighting the screw-down case back.
5. Troubleshooting
If you encounter issues with your Nautica One watch, please refer to the following common problems and solutions:
- Watch Not Running:
- Check if the crown is fully pushed in and screwed down.
- The battery may need replacement. Consult a professional watchmaker.
- Date Not Changing:
- Ensure the time is set correctly, passing midnight for the date to advance.
- Avoid setting the date between 9 PM and 3 AM. If adjusted during this period, reset the time past 3 AM and then set the date.
- Chronograph Hands Not Resetting to Zero:
- This may indicate a need for chronograph hand calibration. Refer to a professional watchmaker for adjustment.
- Condensation Under Crystal:
- Small amounts of condensation that disappear quickly are usually normal. Persistent condensation or large droplets indicate a loss of water resistance. Immediately take the watch to a service center to prevent internal damage.
6. Specifications
| Model Number | NAPNOS306 |
| Case Diameter | 48mm |
| Case Material | Recycled (85%) Stainless Steel |
| Crystal Material | Mineral Glass |
| Movement Type | Quartz Chronograph |
| Water Resistance | 100 meters (330 feet) |
| Strap Material | Recycled (85%) Stainless Steel Bracelet and Silicone Strap |
| Manufacturer | Timex |
| ASIN | B0BSZ6GC4F |
| Package Dimensions | 7.01 x 4.21 x 2.95 inches |
| Item Weight | 4.16 ounces |
7. Warranty and Support
Nautica watches are manufactured by Timex. For specific warranty information, please refer to the warranty card included with your purchase or visit the official Nautica or Timex website.
For customer support, service, or repair inquiries, please contact the manufacturer's customer service department. Keep your proof of purchase and model number (NAPNOS306) readily available when contacting support.
Manufacturer: Timex





