TABLE 1             END-OF-DIVE LETTER GROUP   Start Depth        M     FT                          
  OTIS INTERPRETATION[1]
00
 MAXIMUM DIVE TIME (MDT)[2] 00 DIVE TIME REQUIRING DECOMPRESSION[3]
  00 NO. MINUTES REQUIRED AT 15' STOP
 
  
  FOR TRAINING USE ONLY   12 40 > 5 15 25 30 40 50 70 80 100 110
130
 150
    5
  15 50 >   10 15 25 30 40 50 60 70
80
   100
  5
    18 60 >   10 15 20 25 30 40 50
55
 60   80
  TABLE 3 REPETITIVE DIVE TIMETABLE   5   7
  21 70 >   5 10 15 20 30 35 40 45 50 60 70
  5 8 14
  47 RESIDUAL NITROGEN TIME (RNT)   24 80 >   5 10 15 20 25 30
35
 40   50 60
  33 MAXIMUM DIVE TIME (AMDT)   5   10 17
  27 90 >   5 10 12 15 20
25
 30   40   50
  5   7   18
    30 100 >   5 7 10 15 20 22 25     40  
    5     15  
  33 110 >     5 10 13
15
 20     30    
  5     7    
    36 120 >     5 10
12
 15     25 30    
    5     6 14    
  39 130 >     5
8
 10         25    
  5         10    
             
  A B C D E F G H I J K L
           
           
           
M 12 15 18 21 24 27 30 33 36 39 NEW
FT 40 50 60 70 80 90 100 110 120 130 GROUP  
  7 6 5 4 4 3 3 3 3 3 < A
24:00 24:00 24:00 24:00 24:00 24:00 24:00 24:00 24:00 24:00 24:00 24:00
  123 74 50 41 31 22 19 12 9 5 0:10 3:21 4:49 5:49 6:35 7:06 7:36 8:00 8:22 8:51 8:59 9:13
  17 1 11 9 8 7 7 6 6 6 < B
3:20 4:48 5:48 6:34 7:05 7:35 7:59 8:21 8:50 8:58 9:12
  113 67 44 36 27 18 15 9 6   0:10 1:40 2:39 3:25 3:58 4:26 4:50 5:13 5:41 4:49 6:03
  25 21 17 15 13 11 10 10 9 8 < C
1:39 2:38 3:24 3:57 4:25 4:49 5:12 5:40 5:48 6:02
  105 59 38 30 22 14 12 5     0:10 1:10 1:58 2:29 2:59 3:21 3:44 4:03 4:20 4:36
  37 29 24 20 18 16 14 13 12 11 < D
1:09 1:57 2:28 2:58 3:20 3:43 4:02 4:19 4:35
  93 51 31 25 17 9 8       0:10 0:55 1:30 2:00 2:24 2:45 3:05 3:22 3:37
  49 38 30 26 23 20 18 16 15 13 < E
0:54 1:29 1:59 2:23 2:44 3:04 3:21 3:36
  81 42 25 19 12 5 4       0:10 0:46 1:16 1:42 2:03 2:21 2:39 2:54
  61 47 36 31 28 24 22 20 18 16 < F
0:45 1:15 1:41 2:02 2:20 2:38 2:53
  69 33 19 14 7           0:10 0:41 1:07 1:30 1:48 2:04 2:20
  73 56 44 37 32 29 26 24 21 19 < G
0:40 1:06 1:29 1:47 2:03 2:19
  57 24 11 8             0:10 0:37 1:00 1:20 1:36 1:50
  87 66 52 43 38 33 30 27 25 22 < H
0:36 0:59 1:19 1:35 1:49
  43 14                 0:10 0:34 0:55 1:12 1:26
  101 76 61 50 43 38 34 31 28 25 < I
0:33 0:54 1:11 1:25
  29 4                 0:10 0:32 0:50 1:05
  116 87 70 57 48 43 38 AVOID REPETITIVE DIVES OVER 100 FEET < J
0:31 0:49 1:04
  14             TABLE 2 - SURFACE INTERVAL TIME (SIT) TABLE[4] 0:10 0:29 0:46
  138 99 79 64 54 47   < K
0:28 0:45
                TIME RANGES IN HOURS:MINUTES 0:10 0:27
  161 111 88 72 61 53   < L
0:26
                                            0:10
[1]
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.

Ascend 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.

Use 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.
[2]
Maximum Dive Time (MDT). This is the time you can spend at a given depth without having to do a required decompression stop during ascent. This time is also known as the Maximum Allowable Dive Time.
[3]
Decompression Stop. This is a point in a dive where you stop at a specified depth for a specified time during ascent to allow nitrogen outgassing before continuing your ascent or surfacing.
Precautionary Decompression Stop. This is a stop at 5 meters (15 feet) for 3 minutes as a safety precaution when you have not exceeded the Maximum Dive Time. You should perform such a stop at the end of every dive. It is also known as a Safety Stop.
Required Decompression Stop. This is the amount of time specified by the NAUI Dive Tables, that you must spend at 5 meters (15 feet) whenever you exceed the Maximum Dive Time. Other tables specify additional stop depths for deeper or longer dives.

[4]
Surface Interval Time (SIT). This is the time spent on the surface between dives. During this time, your body is eliminating excess nitrogen. Your Letter Group will change and move closer to the beginning of the alphabet, depending on how long you are on the surface.