Reading Dive Tables




About: Engineer making renewable energy products for African entrepreneurs.

How to read a PADI Recreational Dive Planner... If you've ever wondered what the hardest part of scuba diving is - this is it. And I'll give you a brief introduction on how to do it.

As it seems quite a few people are into kite boarding (well, admin mostly), I figured I would share some other water related fun considering I live close to some of the top rated dive spots :P Next I'll show you how to make $30 equipment have the same functionality as the $60+ stuff ;)

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Step 1: All You Need Is a Your Dive Table and Your Brain.

First, I want to reiterate why nowadays scuba diving is safe and sex is dangerous. A great deal of time and research was put into how diving stresses the human body. Many people risked their lives (and likely a few deaths we have not heard of) to work on this research to make scuba diving safer for the recreational diver.

The reason scuba is considered 'safe' nowadays is a direct result of diver TRAINING in addition to advancements in equipment. Dive shops refuse to fill my father's old tanks due to these advancements. Therefore, DO NOT ATTEMPT WITHOUT PROPER TRAINING AND CERTIFICATION. Hopefully, these instructions will dispel some fears about diving in general and show that almost anyone can do it.

Everything you see in parenthesis () -- is an example dive to follow ;)

Step 2: Side 1 - Table 1 (Left Side)

This table categorizes dive depth and 'bottom time.' Bottom time is considered the time it takes to reach depth + actual bottom time + time to surface. This allows for some margin of error. ALWAYS round up.

Also on this table is:
"Safety Stop Required" (gray boxes) - this means you must stop at 15 feet for 3 minutes before surfacing.

"No Decompression Limits" (black boxes) - if you exceed this time for less than 5 minutes, take a safety stop at 15 feet for 8 minutes, and stay out of the water for at least 6 hours before another dive. If you are there for more than 5 minutes, take a 15 minute (air supply permitting) safety stop at 15 feet and stay out of the water for at least 24 hours. This depth should only be exceeded in case of emergency. Loosing equipment is NOT an emergency. Should you feel any effect of decompression sickness after you surface, seek medical attention ASAP (hyperbaric chamber). This is not something you should just walk off. Plan your dives and this won't happen ;)

"Pressure Group" - Categorized A-Z to make reading the next two tables easier.

Step 1: Select your planned dive depth ('60' feet)

Step 2: Select your planned bottom time ('17' minutes - pressure group 'E')

Step 3: Dive OR Goto Table 2 if you plan to do multiple dives

Step 3: Side 1 - Table 2 (Right Side)

This is the surface Interval Credit Table. If you plan on taking more than 1 dive, this tells you how much 'credit' you have earned. The longer you are under compression breathing compressed air - the more nitrogen saturates your tissues. The longer you are out of these conditions, the more nitrogen is able to safely leave.

Step 4: Select your surface time from the table. ('0:08-0:16')
Step 5: Slide your finger down to bottom of table and read your new pressure group. ('D')
Step 6: See Side 2 - Table 3

Step 4: Side 2 - Table 3

This table is the "Repetitive Dive Timetable." Based on the residual nitrogen levels from the previous dive, this table adjusts your new max bottom time for your next dive.

What you'll see:
"Depth (feet)"
"Pressure Group at End of Surface Interval" - the letter you got from Table 2
"Residual Nitrogen Time (RNT)" (white area)
"Adjusted no-decompression time limits"

Step 7: Find your pressure group ('D')

Step 8: Slide your finger across your planned second dive depth row until you hit your pressure group column (let's say 40 feet -- '25/115')

Step 9: Note your new adjusted no decompression limit ('115')

Step 10: Add your RNT ('25') to you're second dive's planned bottom time (lets say 20 minutes). This is now your 'Actual Bottom Time' (ABT - '45').

Step 11: Repeat process as normal from Table 1 using your calculated ABT. At 40 feet, '45' minutes does not exist, so we use '48' feet instead.

Step 5: Other Notes

This table does not apply to dives above 1000ft (say a lake dive).
This table does not apply to rebreathers -- which is really not recreational diving anyway :P
Follow S.A.F.E. Dive - "Slowly Ascend From Every Dive." Ascend no faster than 60 feet per minute (about the speed your bubbles rise)

Should you expect strenuous conditions (cold, current, etc.) - add 10 feet.
Each successive dive should be shallower than the last.
If you plan on flying, wait at base level for at least 12 hours to avoid decompression sickness.
Never EVER hold your breath while breathing compressed air.
Always dive with a buddy, and don't forget to check both octopus-rigs (secondary regulator).
Touch Coral - it dies. It is as simple as that.

There are special circumstances for dives in groups W, X, Y, and Z. Get certified to learn why it is important to know these thing :P

We're always warned: "Since Little is presently known about the philological effects of multiple dives over multiple days, divers are wise to make fewer dives and limit their exposure toward the end of a multiday diver series."

Yes, I have a certification with PADI.




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    24 Discussions


    2 years ago

    Было бы желательно, чтобы практиковать подводное плавание, правда я абсолютно новичок, что мне начать? Для того, чтобы поехать в Египет, как там сказано, что все обучение во много раз дешевле, и сразу же можно погружаться в море. Или все включено подводное плавание ( ) будет подходящим для начинающих тоже?


    5 years ago on Introduction

    This is dangerous as Skirmishmonkey says. Learning to dive is not something to take lightly and learn from someone whose qualifications are unknown. You should only learn to dive from a trained professional.

    1 reply

    Reply 4 years ago on Introduction

    Don't be silly - information is power.

    Yes, you should be trained and certified by a professional; but taking information from people is ridiculous. I'm using this post as a reference and memory refresher right now although I've taken the course. The information should be reviewed for accuracy, yes - but not removed.


    7 years ago on Introduction

    I still use the PADI Dive tables but totally agree that you need to have a good standard of tuition to enable you to understand the tables and work with them properly. At the end of the day it is still the individual diver and their interpretation of the PADI Dive Tables. Make sure you have proper training prior to using the tables so you really know what you are doing. For those that are at a proficient standard and use the tables regularly i found a good copy of the PADI Dive tables at this blog:

    They also have some interesting articles on NAUI and comparisons with the PADI dive Tables if you are interested.

    Instructables should remove this post as some of the information contained herein is dangerous to the point that it could kill someone.

    I am a PADI professional diving instructor (have been diving for more than 10 years and logged 5,000+ dives).

    For example you say, that plan your dive and decompression sickness won't happen. You neglect to mention that it can happen even if the dive is planned and adhered to. In cases where the diver is dehydrated, ill, cold, overweight, etc.

    You also leave yourself open to litigation if someone reads your 'ible and then has a diving incident because they learned the RDP based on the information herein.

    If anyone wants to learn to dive, then please learn with a reputable dive professional, not something you read on the internet. In fact PADI has a policy of suing anybody who attempts to teach it's method (including dive tables) without the proper instructor level certification.


    9 years ago on Introduction

    You said, "steel tanks are now obsolete." Not so. Steel tanks are great to use, especially when diving with a lot of neoprene. (In cold water, for example, you want extra those extra ml of insulation.) The negative buoyancy of the steel tanks means you don't have to carry as much lead. This is a good thing.

    3 replies

    Reply 9 years ago on Introduction

    Damn straight! And Steelys tend to last longer than Allys, before failing a hydrostatic test.


    Reply 9 years ago on Introduction

    Yeah, I've been meaning to edit that (someone sent me an eMail a while back) :p My father has some steel tanks from when he was young... It's some scary stuff compared to modern designs :p


    9 years ago on Introduction

    Thanks for teaching Dive tables. Dive tables are a great resource for scuba divers. A dive table is a chart that is usually printed on cards or come in booklets that will help divers to determine different aspects of particular dives relating to breathing gas and when to take decompression stops during the dive. Scuba Diving Sharm El Sheikh These dive tables can be found in many different places there are PADI dive tables, NAUI dive tables, navy dive tables and EAD dive tables. Most dive tables are created to assume that the diver will immediately proceed to the depth indicated and stay there for the full duration of the dive without visiting other depths and before returning to the surface.


    9 years ago on Introduction

    Looe Key is one of the best places to dive in the US.


    9 years ago on Introduction

    (Yay, posting a 3.5-year late comment.)

    Thanks for the explanation!

    Just fixing a typo that might be confusing to someone just learning about this: you write in step 2 "hyperbolic" chamber but meant "hyperbaric."

    2 replies

    Reply 9 years ago on Introduction

    Nice catch - fixed :)

    Interesting to note - firefox wants to correct "hyperbaric" to hyperbolic or hyperbola :p


    Reply 9 years ago on Introduction

    I know--it made me do a double-take.  We need an "Add to Global Dictionary" option. :)


    9 years ago on Step 4

    on step 11 you made an error...Last sentence should read "instead of 48' feet =48' minutes instead"...and you should use the yellow comment boxes you used on table 1 to highlight some of the tables samples used on table 2. It would make it easier for the reader and keep it consistent with the instructable..Just a thought. tks for explaining the PADI table.


    9 years ago on Introduction

    Good job! My wife and I are both divers. She was actually working on her Divemanster cert when she was diagnosed with Lupus (about 5 years ago). I was too poor to buy a dive computer (back when we dove regualrly), and this is a great refressher. Now my kids are old enough to dive, and I'm sure they'll be learning the table soon.


    10 years ago on Introduction

    Having learned to dive in 1985 (yeah, I'm old...) the PADI charts were the ONLY thing I used. Dive computers were what we had between our ears, and our charts were The Word of God. Nobody that I learned to dive with, nor any instructor I had, ever got 'bent' by following the charts. Good Instructable, and maybe you've kept someone out of 'The Chamber'.


    12 years ago on Introduction

    Nice post thanx. i am thirteen and have been diving since i was 10. i have hardly ever used my tables even though i have done 94 dives and have almost completely forgotem how to use them so thanks for the reinder!


    12 years ago

    thanks for refresher. I'm going for my nitrox tommorow and needed that.