■ The watch will not enter the Diving Mode.
LOW or HML ﬂ ashing on the screen indicates that the watch is in the charge recovery state. The watch
will not enter the Diving Mode while it is in the charge recovery state.
■ LIMIT ERR appears when I try to enter the Diving Mode.
This indicates that the reference pressure for setting the 0-meter depth is outside of the sensor's allowable
measuring range. If the high-altitude limit pressure is 530 hPa or lower, a LIMIT ERR will occur. If the
water depth limit pressure is 9,500 hPa or greater, a LIMIT ERR will occur.
■ The watch won't enter the Timekeeping Mode.
If you accidentally enter the Diving Mode while in an aircraft or any other vehicle where there are large
changes in air pressure, the watch will interpret the current pressure as being underwater (depth of 1.5
meters or greater). In this condition, the watch will not return to the Timekeeping Mode.
If this happens, hold down C for about 10 seconds to force the watch to return to the Timekeeping
Do not use the above operation to force the watch into the Timekeeping Mode while diving.
■ The warning mark ( ) is ﬂ ashing on the display.
Refer to "Troubleshooting when a Flashing Warning Mark ( ) Appears" (page E-62).
■ The depth reading does not show 0.0 meters, even when I am on the water surface.
If there is a major change in barometric pressure (due to weather) between the start of the dive and the
end of the dive, or if the barometric pressure on the water surface where the watch is being used is
greater than the standard atmosphere, the water depth value may not return to 0.0 meters at the end of
Entering the Diving Mode while in the water (water pressure equivalent to a depth of 1.5 meters or less)
will cause a water depth of 0 meters to be displayed at the standard atmosphere of 1,013 hPa.
■ Display illumination will not light.
Frequent use of illumination over a short period will cause the HML marks to ﬂ ash (indicating the charge
recovery state) and disable illumination.
The watch may have been subjected to strong shock, causing malfunction of illumination. If this happens,
contact an authorized CASIO service center.
Once you use illumination in the Diving Mode, it will become disabled until you complete your dive.
Taking Direction Readings
■ ERR appears following ﬁ gure 8 calibration.
ERR will appear on the display and calibration may not be possible indoors or in other areas where strong
or weak magnetism is present.
Move away from any potential source of strong magnetism and try taking a reading again. If ERR
continues to be displayed, the problem may be due to a previous successful calibration operation, and
calibration under current conditions that will not improve the calibration result.
Take a direction reading and check if it is correct.
If the direction reading is wrong and if ERR continues to appear even if you move away from the
source of strong magnetism, contact an authorized CASIO service center.
■ Abnormal magnetism detection, indicated by the ﬂ ashing ﬁ gures on the display.
Move away from any potential source of strong magnetism and try taking a reading again.
If abnormal magnetism is detected again when you retry, it could mean that the watch itself has
become magnetized. If this happens, continue to keep away from the source of strong magnetism,
perform ﬁ gure 8 calibration or 3-point calibration, and then try taking a reading again. See "To perform
ﬁ gure 8 calibration" (page E-70), "To perform 3-point calibration" (page E-72), and "Location" (page E-78).
Whenever you have a sensor malfunction, take the watch to your original retailer or nearest authorized
CASIO distributor as soon as possible.
■ I can't change the temperature and water depth display units.
When TYO (Tokyo) is selected as the Home City, the water depth unit is set automatically to meters (m)
and the temperature unit to Celsius (°C). These settings cannot be changed.
■ Temperature readings are incorrect.
Since the temperature sensor is inside the watch, temperatures displayed by the watch are watch body
When measuring air temperature, readings can be affected if you are wearing the watch, by exposure
to direct sunlight, by water splashing onto the watch, etc. For accurate air temperature measurements,
remove the watch from your wrist, wipe away any water on the watch, and place the watch in the shade
in a well-ventilated location.
It takes about 20 to 30 minutes before the temperature of the watch becomes the same as the air
When measuring water temperature, your body temperature has almost no effect on measurements.
However, sudden changes in water temperature can take up to about ﬁ ve minutes to be reﬂ ected in
temperature readings by the watch.
There is something wrong with the sensor. This could be due to nearby strong magnetic force. If ERR
continues to appear even after multiple attempts to calibrate after moving away from the source of the
magnetism, contact your original retailer or CASIO service center. See "Location" (page E-78).
■ The watch does not resume operation after I expose it to light.
This can happen after the power level drops to Level 5 (page E-10). Continue exposing the watch to light until
the battery power indicator shows "H" or "M".
■ H, M, and L are all ﬂ ashing on the display.
The watch is in the charge recovery mode. Wait until the recovery process is complete (about 15 minutes).
The watch will recover more quickly if you place it in a brightly lit location.
Performing repeated illumination and/or sensor reading operations over a short time period can cause
a sudden drop in watch's charge. This will cause the watch to enter the charge recovery mode. The
watch is in the charge recovery mode when H, M, and L are all ﬂ ashing on the display. The charge
recovery mode is the same as a low battery charge state. Access to some functions is limited while the
watch charge is recovering. Normal operation will resume after recovery is complete. For more
information, refer to "Power Levels" (page E-10).
Flashing H, M, L indicators or a ﬂ ashing CHG indicator means that the charge level of the watch is
extremely low. Immediately expose the watch to light to charge it.
See "Radio Controlled Atomic Timekeeping" (page E-14) for information about adjusting the time setting
according to a time calibration signal.
Operation Guide 3445
■ Depth readings are incorrect.
When the watch enters the Diving Mode, it sets the current ambient pressure as 0 meters. Because of
this, you should always enter the Diving Mode while on the water surface. If you entered the Diving Mode
while under water, reset 0 meters on the water surface. Refer to "To reset 0-meter depth manually" (page
Especially during the summer months, direct sunlight can cause the watch to become abnormally hot. If
this happens, leave the watch in the water for two to three minutes to acclimate before using it. See
"Precautions During Use" (page E-49).
Subjecting the watch to strong shock can affect the accuracy of the depth measurements. If this happens
immediately contact an authorized CASIO service center for inspection and sensor adjustment.
This watch displays sea water depth. Fresh water depth can be obtained by multiplying the displayed
depth value by 1.025.
■ Log data is not being recorded.
Log data is recorded only while the watch is measuring a depth of 1.5 meters or less. Immediately after
entering the Diving Mode, the watch measures water depth every 10 seconds. If you suddenly dive into
the water from a boat or other location, measurement timing may cause a delay in the start of memory
recording. When water depth is 0.3 meters or less, measurements are taken ever second. Because of
this, it is recommended that, while on the water surface, you lower your wrist for about 10 seconds to start
If a battery error occurs (indicated by HML ﬂ ashing) or if a sensor error occurs during a dive, data up to
the point that the error occurred will be recorded, but subsequent log data will not be recorded. For more
information, refer to "Charging the Watch" (page E-9) and "Power Levels" (page E-10). If a sensor malfunction
occurs, contact an authorized CASIO service center.
■ While performing 3-point calibration, the watch returns to standby for calibration of Point 1.
The calibration procedure needs to be restarted because an error occurred during calibration or for some
Perform calibration of Point 1 again.
■ ERR appears after 3-point calibration is complete.
If ERR appears, it could mean there is something wrong with the sensor or that there is a strong source of
Move away from any potential source of strong magnetism and try calibrating again.
If ERR continues to appear even after multiple attempts to calibrate, contact your original retailer or
CASIO service center.
■ The direction information indicated by the watch is different from that indicated by a backup
Move away from any potential source of strong magnetism, perform 8 calibration or 3-point calibration,
and then try taking a reading again. For more information, refer to "To perform ﬁ gure 8 calibration"
(page E-70), "To perform 3-point calibration" (page E-72) and "Location" (page E-78).
■ Direction readings produce different results at the same location.
Move away from any potential source of strong magnetism and try taking a reading again. See
"Location" (page E-78).
■ I am having problems taking direction readings indoors.
Indoors, strong and/or weak magnetic force and other factors can create a magnetic ﬁ eld that cannot
exist in geomagnetism. Because of this, correct measurement may not be possible indoors. See
"Location" (page E-78).
If the temperature displayed by the watch is very different from temperature readings by another reliable
measuring device, you can adjust readings to correct for errors.
See "To calibrate the temperature sensor" (page E-94).
■ "ERR" appears on the display while I am using a sensor.
Subjecting the watch to strong impact can cause sensor malfunction or improper contact of internal
circuitry. When this happens, ERR (error) will appear on the display and sensor operations will be disabled.
Water Depth Reading
If ERR appears while a reading operation is being performed in a sensor mode, restart the operation. If
ERR appears on the display again, it can mean there is something wrong with the sensor.
Even if battery power is at Level 1 (H) or Level 2 (M), the Digital Compass Mode, Thermometer Mode,
or Diving Mode sensor may become momentarily disabled if there is not enough voltage available to
power it sufﬁ ciently. In this case, ERR will appear on the display. This does not indicate malfunction,
and sensor operation should resume once battery voltage returns to its normal level.
If ERR keeps appearing during a reading operation, it could mean there is a problem with the
■ The current time setting is off by hours.
Your Home City setting may be wrong (page E-30). Check your Home City setting and correct it, if necessary.
■ The current time setting is off by one hour.
If you are using the watch in an area where time calibration signal reception is possible, see "To conﬁ gure
Home City and summer time settings" (page E-30).
If you are using in the watch in an area where time calibration signal reception is not possible, you may
need to change your Home City's standard time/daylight saving time (DST) setting manually. Use the
procedure under "To change the current time and date settings manually" (page E-32) to change the standard
time/daylight saving time (DST) setting.
Time Calibration Signal
The information in this section applies only when LIS, LON, MAD, PAR, ROM, BER, STO, ATH, MOW,
HKG, BJS, HNL, ANC, YVR, LAX, YEA, DEN, MEX, CHI, NYC, YHZ, YYT, TPE, SEL, or TYO is selected
as the Home City. You need to adjust the current time manually when any other city is selected as the
■ The display shows the ERR indicator when I check the result of the latest receive operation.
Performing a button operation
while a receive operation is
ongoing will cancel it. Also,
Keep the watch in an area where reception conditions are good
moving the watch during a
while the signal receive operation is performed.
receive operation will interfere
Bearing Reading in
the Diving Mode