PADI O/W no tables

[tom lauder]

Thanks everyone, I didn't realise tables were so out of favor these days. All my previous diving was done on tables so I understand the principles behind them just not PADI tables. I will get my hands on the PADI tables somewhere and familiarise myself with them using some of the suggested resources. I guess it's really an exercise in nostalgia for me. Until I get a computer of my own to learn on I revert to what I knew which was tables.

 

[rsingler]

Sorry. Just saw this thread. I think this might be the resource you were looking for to use the PADI tables. It's not a theory discussion; you'll get that from the other suggestions in this thread. But it comprehensively teaches you how to use the PADI RDP.
I applaud your going this deep into the manual practice from the pre-computer era. Even if you never use the tables again, and recognizing @boulderjohn 's caveat about not trying to use these as a backup for a computer failure, it's still nice to have the mental picture of changing pressure groups and surface intervals.
The most enjoyable mental exercise for a deeper understanding, is to use the tables to determine the required surface interval for a second dive to X depth and Y time. It's of no practical value, but it does cement the notion of time needed for offgassing.
For home practicing (for nostalgia or whatever, lol) there are screenshots of the tables (violating copyright of course) out there on the Web.

 

[tom lauder]

Thank you, that's exactly what I was looking for.

Sorry. Just saw this thread. I think this might be the resource you were looking for to use the PADI tables. It's not a theory discussion; you'll get that from the other suggestions in this thread. But it comprehensively teaches you how to use the PADI RDP.
I applaud your going this deep into the manual practice from the pre-computer era. Even if you never use the tables again, and recognizing @boulderjohn 's caveat about not trying to use these as a backup for a computer failure, it's still nice to have the mental picture of changing pressure groups and surface intervals.
The most enjoyable mental exercise for a deeper understanding, is to use the tables to determine the required surface interval for a second dive to X depth and Y time. It's of no practical value, but it does cement the notion of time needed for offgassing.
For home practicing (for nostalgia or whatever, lol) there are screenshots of the tables (violating copyright of course) out there on the Web.

 

[teonchagi]

I just finished my OW class last month and did everything with the tables. I was scared of it at first, but had fun with it by the end. I had to take a test on it and everything. I was also diving with my computer each time, but it was neat to work out the pressure groups. I'm glad I learned how...but I didn't whip out the table this weekend at the lake. I just used my computer...which I still need to really learn to use more than just for logging.

 

[boulderjohn]

I just used my computer...which I still need to really learn to use more than just for logging.

That is one of the criticisms of the tables version of the course. It teaches you to use a methodology you will then ignore and fails to teach you methodology that you will actually use.

 

[Neilwood]

That is one of the criticisms of the tables version of the course. It teaches you to use a methodology you will then ignore and fails to teach you methodology that you will actually use.

And also fails to track "real world" diving where you might not be at a regular depth the entire dive. Yes you can use multi level tables but, for a lot of diving out there, they are still at best a wild ass guess at the actual Nitrogen loading.

I did a couple of dives within a gully at the weekend. The gully has a variable depth bottom where at some points rocks are blocking it so it lifts by about 10 ft and then dips deeper after the rocks are clear. You can either sit at a fixed depth (which means you will be anything from 1ft from the rock or 10ft from the deeper bits) or you can follow the bottom of the gully and see the wildlife. On a table, you assume the deepest depth and that you stayed there the whole dive whereas on a computer you are given a constantly updated picture of what your loading is.

Also, with people teaching tables, students who are actually diving computers end up not knowing what the computer is actually telling them (quite common given the amount of posts about "I didn't know I was in deco" or similar). Teach people to use the planning function on their computers and they will see just as well how depth and time affects their loadings.

 

[teonchagi]

I am absolutely that one who understands the tables and has less of an understanding of my computer.

I can change the settings, review dives, and know what the “stuff” on the screen during a dive means. Honestly I have no clue how to use it to plan. I’ll be sitting down with the manual some more before my next dive. Im also already learning the limitations of a one button computer...

 

[rsingler]

I must be missing something in this discussion. We are implying that it's one or the other.
For me, teaching computer ONLY is like driving to someplace new with ONLY your GPS. You're just following the numbers blindly.
Dive until NDL time reaches 5 min, or 2 min, or zero, and then go up a bit. If you're air integrated, maybe watch "Dive Time Remaining" as well, assuming your instructor taught you about what your computer is telling you. Does your computer give you the shorter of the two times remaining (gas or NDL) for your current depth? It's no different than watching your SPG, if you know what you're seeing. Or do you have to watch TWO numbers (GTR and NDL)?
So I get all that, and as an instructor, I think it's one's responsibility to know the student's computer and teach use of the tracking functions.

But planning? How do we teach a student to "plan" JUST with a computer? Only a few computers have simulation modes. You can do a little with the clumsy computer simulator that one agency supplies. There are a couple others out there for purchase, but they all share the same deficiency: they don't PLAN as much as they let you watch a dive in high speed to see the consequences of extra time at depth.
No, there's no "planning". You're just looking at NDLs for a single depth. You can't plan a multilevel dive. After surfacing, a few allow you to look ahead at surface interval times and the NEXT dive. But many don't. For many, you just sit there on the boat and watch your NDLs scroll up until you have enough time for your next dive at your planned depth. That's planning?

As far as I'm concerned, a dive PLAN for a place you've never dived, or for initial instruction, goes much better with a multilevel planner. You can use an eRDPml, or the tables with zero "surface" time to get a new pressure group for the next level. Or you can use the computer simulator on your laptop if you're not actually planning a real dive. Or you can use a free tec program like Subsurface in a "recreational" mode. But the concept is the same: teach the student the two simultaneous issues. 1) shorter NDLs at depth and time "reacquired" with ascent, and 2) the simultaneous gas consequences of being deeper or shallower.
Tell me how to do that without a pencil and paper. Tell me how to do that in a computer's "planning mode." I don't know how to teach a student how to gas plan without some way of looking at GTR vs. NDL with changes in depth. To me, the tables help that. Yes, the Pressure Groups and Residual Nitrogen Time are a PITA and distract from the issue. But working things on paper to see both issues simultaneously is critical, IMO.

The comments above about students taught on tables who don't know what their computer is telling them, is not a criticism of tables. It's a criticism of the instructor. In today's world, nobody dives tables. I get that. So a student who doesn't understand his computer hasn't been taught to dive. But if he's ONLY looked at his dial in training or planning, he may not understand what it's telling him.

In practice, you get used to having a certain amount of tank time and NDL time for a dive you do regularly, and planning is a pretty quick affair. But if I know there is a thing I want to photograph down at 76 feet, and then some more pics I'd like to do up at 40 feet in some new location, my computer (or my tables) won't tell me how big a tank to bring. But also, my computer probably won't be able to tell me if I have enough NDL time for 15 minutes at one and 25 minutes at the other, ahead of time. Tables/eRDPml will.
Just for grins, I ran that thru the $15 eRDPml that I keep on my phone in the PADI library. It took less than 90 seconds to know that I'm not exceeding NDL, and that I can go on up to 30 feet to fool around for as long as I've got gas. Doing a back of the envelope gas plan (at my estimated RMV) will take a little longer, but you can do the same thing with a homemade spreadsheet in seconds. And there are apps out there for the same thing.
Can't do it on the vast majority of dive computers.