Place of dive tables in modern diving

[lowviz]

...//... I am very glad I did because having a basic understanding of older methods means I usually can tell when a computer or other device is telling me rubbish, students who learn solely on computers only vary rarely develop this skill.

Trust, but verify.

 

[MargaritaMike]

Now to somewhat answer the OP regarding the "place of tables ...".
I believe tables have a place for everyone, to wit:

For some it's in the trash,
For some it's in the classroom,
For some it's in their head,
For some it's in their dive bag,
For some it's in a pocket of their BCD or BP/W
For some it's a combination of two or more of the above, and
For some it's in a museum.
I may have forgotten a place, but I think I have covered most bases.

Cheers -

 

[rhwestfall]

Tables don’t work for sawtooth dives at all. The wheel doesn’t even work unless you stick to the multi level calculation that you planned on. How are you supposed to stick to a plan when you have no idea what kind of terrain you’ll encounter in the first place?
Computers are GREAT tools for exploration diving when you have no idea what you’ll be getting into.

I have no beef with computers, and I own multiple models for me and family. I do still use it as a option to pre-plan.... I also use the information a PDC gives me. I blur the generations..... YMMV

 

[rhwestfall]

Being a "diver from the 80's-early 90's", there have been a large amounts of change to "what was then, and this is now". I fall into the trap of "the old ways", yet am interested in evaluating (vs. blindly adopting) what is proposed now. Yeah, we did it differently "back then", and change is hard, but if it is explained why, and passes the litmus test, I will adopt or use alongside my "benchmark" (maybe replace?). I do not "blindly follow", and because I am an engineer, that is likely the reason. YMMV

 

[rongoodman]

I personally see no use for tables in my diving. If I need to pre-plan a dive it will be done with MultiDeco, with which I can match the deco models and conservatism on my computers exactly. If I was still doing trimix dives I would also have Ratio Deco available as a sanity check.

 

[halocline]

I haven't read all the pages of this thread, so apologies if I'm repeating someone. I'm not sure the tables themselves are that important for OW training, BUT (and it's a Kim Kardashian-sized but) I think it is very important that new divers understand the basics of how decompression sickness happens and what specific dive behaviors are risky. I think it's also very important that they some idea about NDL times for common depths, and have a sense of what to do when they might be near those limits, i.e, take a longer safety stop, don't ascend too quickly.

Now, I'm not sure how you teach those concepts to someone without referring to the tables, at least in simplified form.

 

[BRT]

I believe the PDC gives a much better understanding of nitrogen uptake and offgassing than tables ever could. For the first dive you are basically looking at a set of tables on the computer. 60 feet for 55 minutes and so on. As you dive you find out that you take in less nitrogen as you go shallower and more as you go deeper and you get a sense of the speed when you go deep. Second dive you can see how the first dive's nitrogen is affecting your available bottom time before the dive and how staying shallower helps. Tables could never show you the same permutations.

I can't imagine anyone diving Cozumel using tables and staying anywhere near us, and we seldom get anywhere near our computers limits.

 

[60plus]

I will digress a little from the main post topic with illustration of how to get by without too much technology. I have quite a bit of training and experience navigation that had nothing to do with diving. The circumstances of my second open water dive were such that I was the only student of a very good instructor. As well as the OOA exercise etc he explained the dive plan (using an illustrated poster of the sea bed) and said I could lead if I felt up to it and he would follow and watch my buoyancy and bottom following ability. The route should take about 35 minutes and was basically the shape of a boot laid on its side toe pointing ENE, undulating between 8 and 12 m, Straight out at about 70 degrees from the shore, through a deeper part of the reef, turn 70 degree left, follow reef on left with deeper water (well over 12 m) on right for a while, turn back in 180 degrees over / through reef when I chose. follow seabed with reef on left hand side, when I chose (but before I crossed my outward course, turn right heading back to shore . When seabed was about 7m, turn left and try to stop about 30 m from where we descended, check buoyancy then surface doing safety stop.
When we surfaced he said my buoyancy was pretty good, very nearly there, but my navigation had surprised him. He expected me to go off course and was a bit puzzled when I had not. I explained that in addition to reef and water depth, I had used the sun for direction, and my air gauge as a timer. I use nearly 3.5 bar a minute, so working out the 180 degree turn point was easy and 10 to 12 bar gives me a comfortable safety stop. He was quite amused at my use of the sun for direction. The reef (more like random boulders) was not well defined, without the sun I would not have had a clue where I was going. There was a slight water movement parallel to the shore about 0.2 to 0.3m/sec.

 

[Kevrumbo]

Now to somewhat answer the OP regarding the "place of tables ...".
I believe tables have a place for everyone, to wit:

For some it's in the trash,
For some it's in the classroom,
For some it's in their head,
For some it's in their dive bag,
For some it's in a pocket of their BCD or BP/W
For some it's a combination of two or more of the above, and
For some it's in a museum.
I may have forgotten a place, but I think I have covered most bases.

Cheers -

As a hedge practice against a rare island power outage, the Catalina Hyperbaric Chamber uses only hard copy treatment tables for the patient, and dive tables for the tender and physician in Recompression Therapy. In other words, there is no primary control of chamber operations or treatment/dive table schedules by relying exclusively on an externally plug-powered electronic computer and transducers. An entire USN TT6 or TT6A equivalent can still be completed without interruption or treatment abort in a total power line blackout.

All members of the Volunteer Crew have to know and are drilled in the use of various tables -for example, the basic dive table for chamber-ops personnel on training runs is the HUGI Table:

 

[lowviz]

...//... I think it's also very important that they some idea about NDL times for common depths, and have a sense of what to do when they might be near those limits, i.e, take a longer safety stop, don't ascend too quickly.

Now, I'm not sure how you teach those concepts to someone without referring to the tables, at least in simplified form.

Most especially in simplified form. That is the beauty of tables, they are a first-order approximation to your dive. Easy to commit to memory. Rongoodman and Kevrumbo have serious deco tables committed to memory. I'm sure that they are amused by all this as they have serious insight as to how long to stay at a given depth.

You reinforce my stand on all this. Having something internal to hang on to in times of stress keeps the heart rate down.

I say that you don't get the same insight from a DC. It gives you max depth and average depth. The NDL that it offers is a running 'average'. In plan mode, it will offer insights. However, the best way to grasp what it is saying is to write them down and make a table.