APPD Appendix D 91
Appendix D
DIVE ONE
Reduced Gradient Bubble Model (RGBM)
Dive Table - Air
Sea Level to 2,000 ft / 610 m
DIVE TWO
DIVE THREE
MDT MDT MDT
MAX DEPTHS
MAX DEPTHS
MAX DEPTHS
fsw
130
120
110
100
90
80
70
60
50
40
30
msw
40
36
33
30
27
24
21
18
15
12
9
minutes
10
13
16
20
25
30
40
55
80
110
150
fsw
80
75
70
65
60
55
50
45
40
35
30
msw
24
23
21
20
18
17
15
14
12
11
9
minutes
30
30
40
40
55
55
80
80
110
110
150
fsw
30
30
30
30
30
30
30
30
30
30
30
msw
99999999999
minutes
150
150
150
150
150
150
150
150
150
150
150
This table is designed for scuba dives employing air.
Read the instructions on the back and seek proper training before using this
table or compressed air. Even strict compliance with this table will not guarantee
avoidance of decompression sickness.
Copyright © 2019 NAUI Worldwide. All rights reserved. #35511
RGBM Air Tables
Sea Level to 2,000 ft / 610 m
Abbreviation Key
fsw = feet seawater msw = meters seawater MDT = Maximum Dive Time
SIT = Surface Interval Time DCS = Decompression Sickness fpm = feet per minute
mpm = meters per minute
Rules for Table Use
• Depth measuring devices may require correction for use at altitude and in fresh water to determine
a diver’s actual dive depths and ascent/descent rates.
• Find your first dive’s maximum depth in fsw or msw in the left two columns (Dive One). Follow that row to
the right to get your MDT for Dive One and continue to the next columns under Dive Two to determine permitted
repetitive depth and MDT for your second dive. Continue to the next columns
under Dive Three to determine repetitive depth and MDT for your third dive.
• A minimum SIT of 1:00 hour is required between dive one and dive two and dive three.
• If your actual dive depth is not listed, use the MDT for the next greater depth listed.
• Dive Two may be shallower, but cannot exceed depth and MDT to the immediate right and on the same row
as Dive One. Dive Three may be shallower than the depth listed but may not exceed the MDT in column three.
• The maximum descent rate on all dives is 75 fpm (23 mpm).
• The maximum ascent rate is 30 fpm (9 mpm).
• All dives require a safety stop at about 15 fsw (5 msw) (+/- 3 feet or 1 meter) for 3 minutes.
• Dive 3 may be repeated until the 150 minutes are used. Dive depth may not be exceeded.
For dive 3 or greater, the maximum depth for air is 30 fsw.
• After a single dive in an 18-hour period wait a minimum of 12 hours before flying or ascending to an altitude
greater than 8,000 feet/2438 meters. After two dives wait 15 hours and after three dives wait 18 hours.
• Inverted depth profiles (a shallow dive followed by a deeper dive) and mandatory staged decompression dives
are not permitted while using this table.
• If you accidentally exceed your MDT cease all diving activities for 24 hours. If exceeded by less than 5 minutes,
conduct a decompression stop at about 15 fsw (5 msw) for 6 minutes; if exceeded by 5 to 10 minutes, stop at
about 15 fsw (5 msw) for 9 minutes before surfacing.
• If symptoms of DCS manifest breathe oxygen and evacuate to the nearest recompression facility.
• Example 1: Dive 1 to 130 fsw (40 msw) for 10 minutes, followed by a 1:00 SIT: followed by Dive 2 to 80 fsw
(24 msw) for 25 minutes; followed by a 1:00 SIT; followed by Dive 3 to 30 fsw (9 msw) for 150 minutes.
• Example 2: Dive 1 to 115 fsw (35 msw) for 10 minutes followed by a 1:30 minute SIT; followed by Dive 2
to 71 fsw (22 msw) for 25 minutes; followed by a 1:45 SIT; followed by Dive 3 to 25 fsw (8 msw) for 120
minutes.
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Figure D-2 NAUI RGBM Dive Table for Air Sea Level - 2000 ft (610 m)