Seiko 8R39 Caliber Diver's Watch

Important Safety Precautions

⚠️ WARNING

• Do not attempt to dive with the watch without prior training necessary for diving.
• Do not use the watch for deep dives using helium gas mixtures.
• Before diving, check that the watch is operating normally.

ⓘ ATTENTION

• Please study this brochure and follow the instructions within to ensure the reliable operation of your diving watch.
• Do not operate the crown if the watch is wet or submerged.
• Do not operate the buttons if the watch is wet or submerged.
• Try not to strike the watch against hard objects such as rocks and stones.

Notes marked with WARNING describe conditions and situations that, if instructions are not followed, may lead to severe bodily injury or death.

Notes marked with ATTENTION describe conditions and situations that, if instructions are not followed, may lead to bodily injury or property damage.

PRECAUTIONS FOR USING DIVER'S WATCH

Before diving, check that the watch is operating normally; be sure to follow the precautions described below.

BEFORE DIVE

• Do not use the watch for deep dives using helium gas mixtures.
• When underwater, use the rotating bezel to measure time.
• Check that:
  • the crown is securely fixed.
  • the buttons are securely fixed.
  • there are no visible damages on the watchband and crystal.
  • the watchband is securely attached to the watch case.
  • the watchband is securely fastened and fits snugly on the wrist.
  • the rotating bezel moves smoothly counter-clockwise (its rotation should be neither too loose nor too tight), and that the marker is aligned with the minute hand.
  • the time and date are set correctly.
  • the second hand is operating normally (if not, shake the watch several times in a row for 30 seconds to ensure effective mainspring winding).
• We recommend contacting a SEIKO SERVICE CENTER in case of any malfunction.

DURING DIVE

• Do not operate the crown or buttons if the watch is wet or submerged.
• Try not to strike the watch against hard objects such as rocks and stones.
• The rotation of the bezel underwater may be stiffer. This is not a malfunction.

AFTER DIVE

• After diving, rinse the watch in fresh, clean water to remove seawater, sand, dirt, etc.
• To prevent the watch case from rusting after rinsing, wipe the watch dry.

CONTENTS

• CHARACTERISTICS OF MECHANICAL WATCHES - 162
• PART NAMES - 163
• USAGE - 164
• HOW TO SET TIME AND DATE - 166
• HOW TO USE THE CHRONOGRAPH - 169
• ROTATING BEZEL - 172
• CROWN WITH SCREW-LOCK - 173
• TO MAINTAIN THE QUALITY OF YOUR WATCH - 175
• WHERE TO STORE YOUR WATCH - 178
• PERIODIC CHECKS - 178
• WARRANTY AND REPAIR TIPS - 179
• TROUBLESHOOTING - 179
• ACCURACY OF MECHANICAL WATCHES - 181
• SPECIFICATION - 182

SEIKO CALIBER 8R39 CHARACTERISTICS OF MECHANICAL WATCHES

(with automatic and manual winding)

• The power source for these mechanical watches is the mainspring.
• If the watch has stopped, manually turn the crown approximately 20 times to wind the mainspring and start the watch.
• While the accuracy of quartz watches is measured in monthly or annual variations, the accuracy of mechanical watches is indicated by daily variation (slowing/speeding per day).
• The accuracy of mechanical watches under normal use varies depending on usage conditions (time worn on the wrist, ambient temperature, hand movements, and degree of mainspring winding).
• When exposed to a strong magnetic field, the watch may temporarily speed up or slow down. If exposed to a strong magnetic field, some watch parts may become magnetized. In this situation, demagnetization is necessary. Please consult the store where you purchased the watch.

PART NAMES

Diagram Description: A watch face displaying hour, minute, and chronograph hands, sub-dials for chronograph minutes and hours, a small seconds sub-dial, and a date window. The crown and two push-buttons (labeled A and B) are visible on the side.

• Central Chronograph Second Hand
• Hour Hand
• Minute Hand
• Chronograph Minute Hand
• Chronograph Hour Hand
• Small Second Hand
• Date Window
• Crown
• Button A: Start/Stop Chronograph
• Button B: Reset Chronograph

Crown Positions:

• a) Initial position: For manual winding.
• b) Pulled out to the first click: For date setting.
• c) Pulled out to the second click: For time setting.

* The appearance of the dial may vary depending on the model.

USAGE

These watches are equipped with both automatic and manual winding functions.

• When the watch is worn on the wrist, the mainspring is automatically wound by the movement of the arm.
• If the watch has stopped, it is recommended to wind it manually by turning the crown.

How to wind the watch manually

1. Slowly turn the crown clockwise (towards the 12 o'clock position).
   * Turning the crown counter-clockwise (towards the 6 o'clock position) does not wind the mainspring.
2. Continue winding the watch until the mainspring is fully wound. The small second hand will start moving.
3. Set the time and date before wearing the watch on your wrist.

• There is no need to continue turning the crown once the mainspring is fully wound. However, the crown may continue to turn without damaging the watch mechanism.
• If the watch is fully wound, it will run continuously for approximately 45 hours. With prolonged use of the chronograph, there is a possibility that the watch will run for less than 45 hours.
• When using a partially wound watch, the timekeeping may speed up or slow down. To avoid this, wear the watch for at least 10 hours a day. If you are not wearing the watch and are using it as a desk clock, please wind it every day at the same time.
• If the watch has stopped and the mainspring is not wound, winding the mainspring will not start the watch instantly. This is because the torque (force) of the mainspring is initially small due to the characteristics of mechanical watches. The small second hand will start moving when the torque reaches a certain level after fully winding the mainspring. Shaking the watch from side to side will help start the watch faster.

HOW TO SET TIME AND DATE

• Before setting the date and time, ensure that the watch is running: the mainspring is sufficiently wound.
• Watches equipped with a date function are designed so that the date changes every 24 hours. The date changes at midnight. If the AM/PM function is set incorrectly, the date will change at noon.

1. Pull out the crown to the first click. (The small second hand will continue to move, and the watch's accuracy will not be affected).
2. The date is changed by turning the crown counter-clockwise. Turn it until the date of the previous day appears.
   (Example: If today is the 6th of the month, set the date to '5' by turning the crown counter-clockwise).

⚠️ WARNING: Do not set the date between 20:00 and 2:00. If you do so, the date may change incorrectly and cause a malfunction in the watch.

3. Pull out the crown to the second click when the small second hand is at the 12 o'clock position (the small second hand will stop). Turn the crown until the date changes to the next day. The time is currently set for the AM period (before noon). Continue moving the hands to set the current time.
4. Return the crown to its initial position simultaneously with a time signal.

⚠️ WARNING: The mechanism of mechanical watches differs from that of quartz watches. When correcting the time, set the minute hand slightly before the desired time, and then move it to the correct mark.

Correcting the date at the beginning of the month

Manual date correction is required at the end of each month that has fewer than 31 days.

Example) Set the date for the period before noon on the first day of a month that follows a 30-day month.

1. The watch shows '31' instead of '1'. Pull out the crown to the first click.
2. Turn the crown to set the date to '1', then return the crown to its initial position.

⚠️ WARNING: Do not set the date between 20:00 and 2:00. If you do so, the date may change incorrectly and cause a malfunction in the watch.

HOW TO USE THE CHRONOGRAPH

These watches are equipped with a chronograph function, which can measure time up to 12 hours.

• The term 'chronograph' refers to a watch with a function to measure elapsed time in addition to displaying the time.
• Before using the chronograph, ensure that the central chronograph second hand points to '0'. Press button B to correct the position of the central chronograph second hand.
• Before using the chronograph, ensure that the mainspring is fully wound.

Diagram Description: Watch face highlighting the chronograph hands (central second, minute sub-dial, hour sub-dial) and buttons A (Start/Stop) and B (Reset).

Time shown in example: 10 hours 8 minutes and 42 seconds

Chronograph time shown in example: 6 hours 20 minutes and 10 seconds

CHRONOGRAPH OPERATION

<NORMAL MEASUREMENT>

Start: Press button A.
Stop: Press button A again.
Reset: Press button B.

Example reading: 6 hours 20 minutes 10 seconds

<ACCUMULATED MEASUREMENT>

Start: Press button A.
Stop: Press button A.
Restart: Press button A.
Stop: Press button A.
Reset: Press button B.

Example readings: 2 hours 8 minutes 40 seconds; 6 hours 20 minutes 10 seconds

* Restarting and stopping the chronograph can be done by pressing button A.

HOW TO READ CHRONOGRAPH READINGS

The chronograph minute hand completes one full rotation in 30 minutes. Pay attention to the position of the CHRONOGRAPH hour hand for correct reading of the chronograph minute hand.

<Between 0 and 29 minutes>

Diagram Description: Watch face showing chronograph minute hand around 20 minutes and hour hand below the 0.5 hour mark.

When the chronograph hour hand is before the short mark (0.5 hour marker), read the number of minutes indicated by the chronograph minute hand. In the example above, the time should be read as '6 hours 20 minutes and 10 seconds'.

<Between 30 and 59 minutes>

Diagram Description: Watch face showing chronograph minute hand around 50 minutes and hour hand past the 0.5 hour mark.

When the chronograph hour hand is past the short mark (0.5 hour marker), add 30 to the number of minutes indicated by the chronograph minute hand. In the example above, the time should be read as '6 hours 50 minutes and 10 seconds'.

ROTATING BEZEL

The rotating bezel measures time intervals up to 60 minutes. Set it before diving to monitor how long you have been underwater.

To prevent accidental rotation, the bezel becomes stiffer underwater. Furthermore, for safety, rotation is only possible counter-clockwise, ensuring that the measured time is never shorter than the actual time spent underwater.

1. Turn the rotating bezel to set the marker ◀️ to the desired starting point.
   Turning the bezel is accompanied by clicks. The interval between two clicks is half a minute.
2. The numbers indicated by the minute hand at any given moment represent the elapsed time since the start of the measurement.

Example:

Diagram Description: Watch face with rotating bezel. Minute hand pointing to 30 minutes. Bezel marker aligned with 30. Text indicates 'Start of measurement (10:10 AM)' and '30 minutes elapsed'.

The rotation of the bezel underwater may be stiffer. This is not a malfunction.

CROWN WITH SCREW-LOCK

The watch is equipped with a screw-lock crown to maintain water resistance and prevent accidental operation.

To wind the watch using the crown, first unscrew the crown, then pull it out. It is essential to screw the crown back in after each use.

HOW TO OPERATE THE CROWN WITH SCREW-LOCK

The crown must always be securely screwed in, except when setting the time.

<How to unscrew the crown>

Unscrew the crown by turning it counter-clockwise. After the crown is unscrewed, it can be freely pulled out.

Diagram Description: Crown shown unscrewed.

<How to screw in the crown>

Turn the crown clockwise and simultaneously push it in, as if pressing it against the watch case, until it is fully screwed in and securely locked.

Diagram Description: Crown shown screwed in.

• Before diving, check that the crown is securely fixed in place.
• Do not operate the crown if the watch is wet or submerged.
• Screw in the crown gently, ensuring it is in the correct position. If the crown is difficult to screw in, unscrew it completely and then try screwing it in again. When screwing in the crown, do not use excessive force, as this may damage the threads on the case.

SETTING BUTTONS WITH LOCK

SAFETY LOCK FOR BUTTONS A AND B

Diagram Description: Watch face showing buttons A and B. Arrows indicate 'Locked' and 'Unlocked' positions for each button, controlled by the crown's position.

• Unlock setting buttons: To unlock buttons, ensure the crown is unscrewed.
• Lock setting buttons: To lock buttons, screw the crown in fully. Once the crown is screwed in, the buttons cannot be pressed.

• Before diving, ensure that the buttons are securely fixed in place.
• Do not operate the buttons if the watch is wet or submerged.

TO MAINTAIN THE QUALITY OF YOUR WATCH

Repairing malfunctions in a diver's watch requires professional training and special equipment. If you discover any malfunction in your diver's watch, do not attempt to repair it yourself; send the watch immediately to a SEIKO SERVICE CENTER.

TEMPERATURE REGIME

The main components in mechanical watches are made of metals, which expand or contract depending on temperature. This affects the watch's accuracy. Mechanical watches may slow down at high temperatures and speed up at low temperatures.

MAGNETISM

Diagram Description: Icon representing a magnet with N and S poles.

A strong magnetic field can adversely affect the watch's operation. Do not leave the watch in places where it may be exposed to strong magnetic fields.

CHEMICALS

Diagram Description: Icon representing a chemical flask.

Do not expose the watch to chemical substances such as mercury, solvents, cosmetics, sprays, detergents, glue, or corrosive agents. Otherwise, the watch case, bracelet, etc., may change color, become damaged, or corrode.

PERIODIC CHECKS

Diagram Description: Icon representing a calendar with '2-3 Years' indicated.

We recommend having your watch checked every 2-3 years by an OFFICIAL DEALER or a SEIKO SERVICE CENTER to ensure the integrity of the case, crown, gasket, and water resistance.

CARE FOR THE WATCH CASE AND BRACELET

SHOCKS AND SCRAPES

Diagram Description: Icon showing a watch being dropped or hit.

Try not to drop the watch or strike it against hard surfaces.

PROTECTIVE FILM ON THE WATCH CASE

Diagram Description: Icon showing a watch case with a protective film being peeled off.

If there is a protective film/sticker on the back of your watch case, remove it before using the watch.

To prevent possible corrosion of the case and bracelet, wipe them periodically with a soft, dry cloth.

LUMIBRITE™

'LumiBrite' is a luminescent paint that is completely harmless to humans and the environment, containing no harmful materials such as radioactive substances.

'LumiBrite' is a new development in luminescent paint that absorbs energy from sunlight and light sources in a short period and emits light in the dark. For example, exposing the watch to light with an intensity of over 500 Lux for approximately 10 minutes is sufficient for the 'LumiBrite' coating to emit light for 5-8 hours. However, please note that 'LumiBrite' emits stored light, and therefore, the light intensity decreases over time. The duration of the glowing period may also vary slightly depending on factors such as the brightness of the light source, the distance between the light source and the watch.

If you go diving in places where light does not reach, 'LumiBrite' will only glow if it has absorbed and stored sufficient light. Therefore, before diving, expose the watch to light – considering the factors described above – so that it absorbs and stores sufficient light energy. Otherwise, use the watch with a dive flashlight.

<Information on Luminescence>

• (A) Sunlight
  [Clear sky]: 100,000 Lux [Cloudy sky]: 10,000 Lux
• (B) Indoors (Daytime outside the window)
  [Clear sky]: over 3,000 Lux [Cloudy sky]: 1,000 Lux to 3,000 Lux
  [Rainy weather]: less than 1,000 Lux
• (C) Lighting fixtures (*fluorescent lamp, 40W)
  [Distance to watch: 1m]: 1,000 Lux
  [Distance to watch: 3m]: 500 Lux (average room illumination)
  [Distance to watch: 4m]: 250 Lux

* LUMIBRITE™ is a trademark of SEIKO HOLDINGS CORPORATION.

WHERE TO STORE YOUR WATCH

• Avoid storing the watch for extended periods at temperatures below 5 °C or above 35 °C.
• Do not leave the watch in places where it may be exposed to strong magnetic fields (e.g., near televisions, loudspeakers, or magnetic bracelets) or near sources of static electricity.
• Do not leave the watch in places with strong vibration.
• Do not leave the watch in dusty places.
• Do not expose the watch to chemical substances or gases. (e.g., Organic solvents such as gasoline and thinner, gasoline, lacquer for nails, cosmetic sprays, detergents, glue, mercury, and iodine-based antiseptic solutions.)
• Avoid direct contact of your watch with hot water.

PERIODIC CHECKS

This watch is a precision instrument with many moving parts lubricated with special oil. If the lubrication is insufficient or parts wear out, the watch may show incorrect time or stop. Therefore, it requires periodic checks.

WARRANTY AND REPAIR TIPS

• For repairs or checks, please contact the store where you purchased the watch, or a SEIKO SERVICE CENTER.
• Before the warranty expires, please present your warranty certificate when contacting a SEIKO SERVICE CENTER.
• Warranty conditions are stated in the warranty certificate. Please read it carefully and keep it.

TROUBLESHOOTING

* For any other problems, please consult the store where you purchased the watch.

ACCURACY OF MECHANICAL WATCHES

• The accuracy of mechanical watches is indicated by daily variations, approximately over a week.
• The accuracy of mechanical watches may deviate from the specified range due to slowing or speeding caused by usage conditions, such as the duration the watch is worn on the wrist, hand movements, degree of mainspring winding, etc.
• The main components in mechanical watches are made of metals, which expand or contract depending on temperature. This affects the watch's accuracy. Mechanical watches tend to slow down at high temperatures and speed up at low temperatures.
• To improve accuracy, it is important to regularly supply energy to the balance wheel, which controls the speed of the gear train. The driving force of the mainspring, which powers the mechanical watch, is not uniform when the spring is fully wound or partially wound. The less the mainspring is wound, the weaker its driving force.
• Relatively consistent accuracy can be achieved by wearing the watch frequently on the wrist for automatic watches, and by fully winding the mainspring daily at the same time for manual-winding watches.
• When exposed to a strong external magnetic field, mechanical watches may temporarily slow down or speed up. Watch parts may become magnetized depending on the strength of the magnetic field. In this situation, consult the store where you purchased the watch, as it may require repair, including demagnetization.

SPECIFICATION

• Accuracy indicated above is set at the factory.
• According to the characteristics of mechanical watches, any actual accuracy may fall outside the range indicated above, depending on usage conditions such as wearing time, temperature, hand movements, degree of mainspring winding, etc.