Dive Table Rules
You must understand the following NAUI Dive
Table rules completely. Similar rules will apply to any new set of dive tables
or dive computer that you might use to calculate your dive times.
no faster than 9 meters (30 feet) per minute. This is 0.3 meters (1 foot) every
two seconds. You need a timing device and a depth gauge (or a dive computer) to
measure your rate of ascent. This rate will seem quite slow to you.
the exact or the next greater number listed in the table for your depth. If you
exceed a number in the table, use the next greater number. The depths in the
table range from 12 meters (40 feet) to 39 meters (130 feet) and increase in
increments of 3 meters (10 feet). For example, you round a dive to 12.3 meters
(41 feet) up to a 15 meter (50 foot) dive.
Use the exact or the next
greater number listed in the table for your time. If you exceed a number in the
table, use the next greater number. The times range from 5 minutes to 130
minutes. For example, you round a dive to 15 meters (50 feet) for 41 minutes up
to 50 minutes.
Use the deepest depth you reached during your dive to
determine the dive schedule for your dive. For example, if you do a dive to 18
meters (60 feet), but spend most of the time at 12 meters (40 feet), you must
consider the dive to be an 18 meter (60 foot) dive.
Always make your
deepest dive first when making a series of dives. Plan each of your repetitive
dives to a shallower depth than your previous dive. This might allow you to
outgas nitrogen on progressively shallower dives and prevents you from carrying
progressively larger amount of residual nitrogen on deeper repetitive dives.
Consider any dive shallower than 12 meters (40 feet) to be a 12-meter
(40-foot) dive when planning your dives.
Plan a Surface Interval Time (SIT)
of at least 10 minutes between dives. If your SIT is less than 10 minutes, you
must consider your second dive as part of the first dive. NAUI recommends a SIT
of at least 1 hour between dives.
Use the next greater dive time if your
dive is particularly cold or strenuous. For example, if you do a dive to 18
meters (60 feet) for 22 minutes, the 22 minutes rounds to 25 minutes. However,
if you become chilled during the dive, round the time again to 30 minutes.
Avoid dives that take you right to the no-decompression limit for any
given depth and time combination. If you accidentally overstay your bottom time
or use an incorrect ascent rate on such a dive, you could be in a decompression
situation or suffer DCS. Always allow yourself enough time to make a slow,
comfortable ascent with plenty of air.