| Diving Terms Used by this Watch |
| The following provides an explanation of the diving terms displayed by
this watch along with their basic meanings. |
| <Algorithm> |
 |
This watch employs the calculation formula of the Canadian Defense and
Civil Institute of Environmental Medicine (DCIEM). |
| <Scuba Diving and Skin Diving> |
| This watch automatically distinguishes between skin diving and scuba diving
according to the following conditions, and records log data separately
for each type of diving. |
| * |
Scuba diving: Continuously diving for 3 minutes or more to a depth of 1
m (4 ft) or more |
| * |
Skin diving: Continuously diving for less than 3 minutes to a depth of
1 m (4 ft) or more |
| <No-Decompression Diving and No-Decompression Limit (NDL) Time> |
| No-decompression diving (NDL = No-Decompression Limit) refers to diving
that allows the diver to ascend to the surface without stopping for decompression
during the course of ascending following completion of a dive. The limit
time during which this no-decompression diving is allowed is referred to
as the no-decompression limit time. No-decompression limit time varies
according to the diving depth and diving time of the previous dives. |
| <One Dive> |
| In this watch, one dive constitutes the time from initially diving to a
depth of 1 m (4 ft) (start of dive) from the preliminary dive mode state
to the time the dive mode is terminated (end of dive). |
| <NITROX Diving> |
| NITROX diving refers to diving in which a mixed gas of oxygen and nitrogen
is used that has a higher oxygen concentration than ordinary air tanks.
This watch allows the oxygen concentration (O2%) to be set within the range
of 22% to 50% in the dive plan mode. |
| * |
NITROX diving reduces the diver's risk of decompression sickness by reducing
the nitrogen ratio (%) to a level lower than ordinary AIR diving. However,
increasing the oxygen ratio (%) also invites the risk of "oxygen toxication"
for the diver, a condition that is unpredictable in the case of AIR diving.
In the case of performing NITROX diving, always make sure to receive safety
training relating to NITROX diving in advance. |
| <AIR Diving> |
| AIR diving refers to diving using an ordinary air tank (compressed air
having an oxygen concentration of 21%). This watch uses the term AIR diving
to distinguish it from NITROX diving in which the oxygen concentration
is 22% or higher. |
| <High-Altitude Diving and Altitude Setting> |
| High-altitude diving refers to diving at a high altitude of 300 m (1,000
ft) or more above sea level (such as in lakes, ponds or rivers). Since
this watch calculates no-decompression time when diving by calculating
body nitrogen level based on actual atmospheric pressure periodically measured
while on land prior to diving, special settings are not required during
high-altitude diving. However, water depth is displayed based on seawater
(specific gravity: 1.025) even when diving in fresh water. |
| * |
Since atmospheric pressure at high altitudes differs from that at lower
altitudes where ordinary diving is performed, high-altitude diving requires
special skills. In the case of performing high-altitude diving, always
make sure to receive safety training regarding high-altitude diving in
advance. |
| <Repetitive Diving> |
| Repetitive diving refers to diving that is repeated while there is still
residual nitrogen in the body from the previous dive. The number
of the next dive for repetitive diving is displayed on the second display
of the dive plan mode. |
| <Decompression Diving> |
| This refers to diving beyond the no-decompression limit time. Decompression
diving is extremely dangerous since nitrogen accumulates in the body beyond
allowable levels. Never dive in this manner. |
| <Decompression Stop> |
| This refers to a stop that must be made to ensure the necessary decompression
in the case of having performed decompression diving. It is necessary to
make a decompression stop at a predetermined depth (decompression stop
instructed depth) and predetermined time (decompression stop instructed
time) when ascending. |
| <Safety Stop> |
| Safety stop refers to a temporary stop made during ascending for safety
reasons in order to promote expulsion of nitrogen in the body, and is performed
even if the no-decompression limit time has not been exceeded. In the case
of having dove to a depth of 18 m (60 ft) or more, a safety stop should
always be made at 5 m (15 ft) of depth to ensure safety. |
| <Total Ascent Time> |
| This refers to the minimum time required to ascend to the surface from
the current depth in the case of ascending at the rate of 18 m (60 ft)/min
or less while making a decompression stop in accordance with the decompression
stop instructions during decompression diving. |
| <Body Nitrogen Level> |
| This refers to the amount of nitrogen dissolved in the body as a result
of diving. This watch displays a general indicator of the amount of nitrogen
dissolved in the body in the form of a bar graph. The higher the level
of the black portion of the graph, the greater the body nitrogen level. |
| <Total number of Dives (Log Count)> |
| This indicates the total number of dives for scuba diving. |
| * |
Arbitrarily resetting the number of past dives with the gCAPgmh software provided before using the watch for diving enables this to display the total number of scuba dives made throughout your life. |
| <Dive Date> |
| This is the date (year, month and date) on which a dive was made. |
| <Dive Number> |
| This is the number of dives made in one day. A maximum of 15 dives are
counted per day for skin diving and scuba diving, respectively. |
| * |
This indicates the number of a dive for a particular dive date. The counter
is reset to 1 when the day changes. |
| <Surface Interval Time (S.I. Time)> |
| This refers to the elapsed time following completion of scuba diving (surface
interval time (S.I. Time)). This watch measures surface interval time up
to a maximum of 24 hours. |
| * |
S.I. Time as referred to in the scuba diving log mode represents the elapsed
time from completion of the dive of the previous log until the start of
the dive of the current log. |
| <Dive Time> |
| This is the total time at a depth of 1 m (4 ft) or more during a single
dive. |
| * |
Measurement of dive time starts when first going below a depth of 1 m (4
ft), and stops when depth reaches less than 1 m (4 ft). However, if a dive
is resumed to a depth of more than 1 m (4 ft) within 10 minutes from the
time measurement of dive time stopped, dive time is continued to be measured
from the time measurement stopped. |
| <Time In> |
| This is the time when the depth exceeds 1 m (4 ft) for the first time during
the dive. |
| <Minimum Water Temperature (Min.w.temp)> |
| This is the minimum water temperature encountered during the course of
a single dive. |
| <Maximum Depth (Max. Depth)> |
| This is the depth when having dove the deepest during the course of a single
dive. |
| <Average Depth (Ave. Depth)> |
| This is the average depth during the course of a single dive. |
| * |
This refers to the average value of depth measured for every 5 seconds
of dive time. |
| <Profile Log> |
| The watch displays a simple graph of the changes in depth during a dive. |
| * |
Data relating to depths measured every 5 seconds and water temperature
measured every 5 minutes can be confirmed on a personal computer. |
| <Oxygen Concentration (O2%)> |
| This refers to the ratio (%) of oxygen in the tank used for diving. During
NITROX diving, always make sure to set the oxygen concentration according
to the oxygen concentration of the tank actually used in the dive plan
mode. The oxygen concentration (O2%) can be set within a range of 22% to
50%. |
| <Oxygen Toxication> |
| This refers to a rejection reaction (consisting of symptoms such as dizziness,
nausea and paralysis) that occurs due to the infusion of large amounts
of oxygen into the human body. This condition can be fatal in extreme circumstances. |
| <Partial Pressure of Oxygen in the Body (PO2)> |
| The partial pressure of oxygen in the body (PO2) refers to the absolute
pressure (ATA) of oxygen that acts within the body. The partial pressure
of oxygen in the body is determined by the NITROX oxygen concentration
and depth, and increases as depth becomes deeper. In general, the limit
at which oxygen toxication occurs in the human body is said to be PO2 =
1.6 (ATA). The display of this watch flashes when PO2 is between 1.4 and
1.5, and when PO2 reaches 1.6 or higher, an alarm sounds to warn the diver. |
| <Oxygen Toxication Time (OTT)> |
| Oxygen toxication time (OTT) refers to the limit time of oxygen toxication.
The oxygen toxication time is determined by the NITROX oxygen concentration,
depth and dive time. In this watch, when the amount of time remaining until
oxygen toxication time decreases to less than 10 minutes, the amount of
time remaining until OTT flashes on the display, and when the oxygen toxication
time reaches 0 minutes, an alarm sounds to warn the diver. |