Precautions During Use; Ascent Rate Alarm - Casio 3445 Operation Manual

Sensor error
A sensor error occurs, indicated by display of Err and the fl ashing warning mark ( ) if strong impact or
other force damages a sensor, causes faulty sensor connection, etc.
• Even if an error occurs, dive time measurement will continue if it is
Water depth sensor error
already started.
Hold down C for about three seconds to enter the Timekeeping Mode.
•
If a sensor error occurs, do not use the watch for diving and contact an authorized CASIO service
center as soon as possible for repair.
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High-altitude and fresh water diving
When you enter the Diving Mode, the watch automatically sets ambient pressure as the 0-meter depth
(0-meter reset). This means you can use the watch even when diving in a lake at a high altitude. At a high
altitude that exceeds 5,000 meters (Barometric Pressure: 530 hPa or less), LIMIT ERR will be displayed,
indicating that measurement is not possible.
Note that the watch displays water depth that is converted to seawater depth (Specifi c Gravity: 1.025).
Because of this, your depth when diving in fresh water is actually about 2.5% deeper than the depth
displayed by the watch.
Example
Displayed depth: 20 meters × 1.025 = 20.5 (actual depth)
The watch's ascent rate alarm is triggered by ascent of 10 meters per minute or greater. Note that the
trigger rate is for seawater diving.
Notice that the higher the altitude you dive at, the lower the barometric pressure compared to that at sea
level. This means that there is a greater risk of decompression sickness and other problems than at sea
level. Also note that you should engage in high-altitude and fresh water diving only after completing
applicable special training.
Diving Mode FAQ
1. What is the meaning of the warning mark ( ) on the display?
The warning mark ( ) indicates that some problem has occurred in the Diving Mode. Log data produced
while a warning mark is on the display is unreliable and should not be used for future dive planning, etc. If
a warning mark ( ) fl ashes on the display, refer to page E-62.
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7. What is the maximum dive time that can be measured?
A dive time of up to six hours can be measured for a single log data record. The watch will return to the
Timekeeping Mode if the dive time exceeds six hours. If this happens, log data up to six hours is recorded
in memory.
8. In the case of successive diving and repeat diving, how does the watch determine where one
dive starts and another dive ends?
The watch applies the criteria below when you return to the water surface (depth of 1.4 meters or less) at
the end of a dive.
Successive diving If you resume your dive (to a depth of 1.5 meters or greater) before 10
minutes of surface time elapse, the current log record is kept open and the
new dive is considered as part of the current dive.
Hold down C for about three seconds to enter the Timekeeping Mode. (The
Repeat diving
watch will also return to the Timekeeping Mode automatically if the surface
time exceeds 10 minutes.) Now if you re-enter the Diving Mode, a separate
log record will be started.
9. Can I operate buttons while under water?
The buttons of the watch can be operated while submerged. L turns on illumination, A displays water
temperature, D takes a direction reading, and B registers a time stamp.
10. What happens if I forgot to enter the Diving Mode before starting a dive?
If you enter the water and then enter the Diving Mode while under water (at a depth of 1.5 meters or less),
the watch will not be able to perform 0-meter reset correctly, which will cause a dive measurement start
error (page E-42). The warning mark ( ) will fl ash on the display, or dive time measurement will start from the
point when the Diving Mode is entered. Water depth measurement and log data recording will be
performed, but it should be remembered that data in this case is unreliable.
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15. Are there any precautions when taking the watch on an airplane?
Entering the Diving Mode while fl ying will display a depth value based on your current surrounding air
pressure, which will cause the watch to mistakenly interpret that you are currently under water.
While diving, the watch will not return to the Timekeeping Mode if you hold down C for about three
seconds. This is a safety feature to avoid accidental switching to the Timekeeping Mode from the Diving
Mode during a dive. If you are not diving, you can override the safety feature by holding down C for about
10 seconds to force the watch to return to the Timekeeping Mode. It is important to note, however, that
you should never use this override operation while diving.
16. Does this watch support saturation diving?
No. Never use this watch while saturation diving. Doing so creates the risk of accident and damage to the
watch.
17. What should I do if the watch detects abnormal magnetism during a bearing reading operation,
which is indicated by the fl ashing fi gures in the illustration below?
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 or
3-point calibration, and then try taking a reading again. See "To perform
figure 8 calibration" (page E-70), "To perform 3-point calibration" (page E-72), and
"Location" (page E-78).
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Operation Guide 3445

Precautions During Use

Extreme ambient temperature changes
• Your watch measures pressure using a precision pressure sensor. Temperature extremes due to the
causes below while using it can make proper measurement impossible.
– Leaving the watch in direct sunlight
– Leaving the watch inside a vehicle parked in the sun
In such cases, leave the watch in the water for two to three minutes to acclimate before using it.
A sudden change in temperature while you are using the watch for diving may cause a depth value of 0.1
to 0.3 meters to be displayed while you are on the water surface, or may cause a negative depth error.
If a measurement error occurs, refer to page E-47.
• The operating temperature range (accuracy guaranteed) for the watch's water depth sensor and
temperature sensor is –10°C to 60°C. The operating temperature range (accuracy guaranteed) for the
watch's direction sensor is 10°C to 40°C. Using this watch while ice diving or for other applications that
will cause its allowable operating temperature ranges to be exceeded can cause measurement error
and/or operation error.
Extreme depth fl uctuations
Your watch measures water depth in approximately one-second intervals and displays the result. A
sudden change in water depth can cause the displayed depth to be different from the actual depth. In
addition, a slow surfacing rate no greater than 10 meters per minute is recommended in the case of sports
diving in order to avoid trouble due to lung squeeze, lung problems, the risk of decompression sickness,
and other dangerous problems.
2. What happens if the watch battery goes dead during a dive?
The H, M, and L marks will fl ash on the display to indicate a battery error. If this happens during a dive,
the dive time measurement and the current timekeeping will continue, but water depth measurement,
water temperature measurement, and direction detection operations will be disabled. Also note that log
data stored before the battery error will be retained, but there will be no log data recorded following the
error.
3. Why does data recording start as soon as I enter the water?
Forcefully entering the water can cause you to reach a depth of 1.5 meters or greater immediately after
entry, which will cause data recording to start. If you surface to 1.4 meters or less, dive time measurement
will pause. Then when you resume your dive, dive time measurement will restart.
4. What should I do if log memory becomes full?
Log memory has a maximum capacity of 20 log records. If log memory already has 20 log records,
recording a new log record in the Diving Mode will automatically delete the oldest log record to make room
for the new one.
5. What is the maximum water depth that can be measured?
Water depth can be measured up to 80 meters. Exceeding a depth of 80 meters causes dEEP to appear
on the display. Normal display of the water depth value will resume after you return to a depth of 80
meters or less. In the above case, the maximum depth log data will also show dEEP.
6. What is the maximum temperature (water temperature) that can be measured?
Temperature can be measured within the range of –10°C to 60°C. - -.-°C is displayed when a measured
value is outside the allowable range.
11. What happens to log data and/or surface time measurement if I change the current time or date
setting?
Log data and/or surface time measurement is unaffected if you change the current time or date setting.
12. What happens if I use display illumination too much while diving?
Overuse of illumination, the compass, or other functions that require high power can cause a battery error,
which will limit further availability of illumination and sensors. When a battery error occurs, the display will
continually show only the current time and dive time (up to six hours).
13. How can I maximize operation provided by a battery charge?
A pressure sensor is activated while the watch is in the Diving Mode, which means that the Diving Mode
consumes large amounts of power. Frequent use of the Diving Mode will shorten the life between charges
of the chargeable battery. To maximize battery life, be sure to enter the Diving Mode just before you are
ready to dive, and exit it as soon as possible after completing the dive.
14. Can I use the watch for high-altitude diving?
When you enter the Diving Mode, the watch automatically sets ambient pressure as the 0-meter depth
(0-meter reset). This means you can use the watch even when diving in a lake at a high altitude. At a high
altitude that exceeds 5,000 meters (Barometric Pressure: 530 hPa or less), LIMIT ERR will appear on the
display indicating that measurement is not possible. Note that depth values displayed by this watch are
based on seawater depth (Specifi c Gravity: 1.025), and that your depth when diving in fresh water is
actually 2.5% deeper than the displayed depth.
Fresh water depth = Displayed Depth × 1.025
The watch's ascent rate alarm is triggered by ascent of 10 meters per minute or greater. Note that the
trigger rate is for seawater diving. Notice that the higher the altitude you dive at, the lower the barometric
pressure compared to that at sea level. This means that there is a greater risk of decompression sickness
and other problems than at sea level. Make sure that you complete the special applicable training before
diving at high altitude or in fresh water.

Ascent Rate Alarm

The ascent rate alarm displays a fl ashing warning whenever you ascend from a scuba dive (using a
self-contained underwater breathing apparatus) at a rate of 10 meters per minute or faster.
• The rate of ascent is a general rule of thumb that indicates the speed at which excessive bubble
formation is avoided.
• Breaking this general rule of ascent can lead to decompression sickness. Because of this, the ascent
rate alarm of the watch cannot be disabled by you.
• Note that 10 meters per minute is ascent rate setting for diving in seawater, not fresh water.
Notice that the higher the altitude you dive at, the lower the barometric pressure compared to that at sea
level. This means that there is a greater risk of decompression sickness and other problems than at sea
level.
Important!
• Your watch is not a precision measuring instrument. The alarm function is intended for general
reference only. Be sure to use this watch together with special-purpose equipment.
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