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View Full Version : How well do you know your dive tables



pnevai
09-17-2007, 22:32
A different thread spurred me to ask this question. They still make dive tables, both PADI and NAUI have different ones. So how proficient are you at finding, your bottom and surface interval times on repetitive dive days?

ertechsg
09-17-2007, 22:36
When we did our AOW with St That seemed to be one major subject Nick stressed on us. By the time the class was over I think everyone knew them . Hope I never have to do them again I'll stick with my computer

finflippers
09-17-2007, 22:38
Even tho I dive with a computer I still log all of my dives with using my tables.

pnevai
09-17-2007, 22:49
Yes we do tend to rely on our gadgets don't we, I also use a comp for that primary task. But consider this, Dive tables are unbreakable old tech. If you have a watch, and bother to set it before each dive, and your comp goes belly up during the dive or surface interval, you are not SOL, You can still fall back on the more conservative profile the tables afford and still salvage the day. In more dire situations they can keep you from getting bent, if you calculate what your dive should be like if dived by the tables before hand, and your comp goes on the blink during a dive.

Of course everyone diving gas integrated, comps without a spg / depth gauge backup have bigger problems :)

Mollusk in training

Capt Hook
09-17-2007, 23:09
Always carry a set in my bag just in case.

picxie
09-18-2007, 05:33
I log all my dives using tables, and can use the PADI & SSI ones fine. Have only just bought a computer but I will continue to log as best I can with tables as well.

ScubaJenn81
09-18-2007, 06:57
I have to review after the few winter months that I do not dive, but it comes back pretty fast, as I do not use a computer yet.

gtjason2000
09-18-2007, 07:43
Somewhere between knowing them in my sleep and being able to use the ones I was trained on ok so I rounded down to be more conservative but wait don't you round up to be more conservative?

chinacat46
09-18-2007, 08:37
I teach people to use the tables and the wheel but dive with two computers. If I were to use the tables I'd be sitting out a lot of dives it's a rare dive where I do an actual square profile.

Subaqua
09-18-2007, 09:33
I dive with a computer, but I still use the table to log my dives. I use only the PADI, and if you use it regularly, it's easy, if I stop using it for a while, then I have to think a bit more to remember how it works.

georoc01
09-18-2007, 09:58
I probably depend upon my computer more than a should. And while I have a set of tables, I don't use them between every dive. I am redundant on computers however, especially on trips.

scubasamurai
09-18-2007, 11:10
i follow up all my dives with the tables, computer in hand. plus it is good practice for that one time the computer fails.

chinacat46
09-18-2007, 11:42
You will find in practise that sometimes a dive will be off the table while it is still a non decompression dive on your computer. Tell me what a table would say about the following.

You jump off the boat and notice your buddy's dive knife drifting down. You go after it and finally catch it at 107'. You slowly ascend to 40' and then dive at 40' for 40 minutes. This would be no problem with a computer but unless you are using the wheel the tables will show you are off the table since it assumes you did the whole dive(40+ minutes) at 110'

Its improtant to know and understand tables but tables will restrict your diving which is why I dive with two computers. If one craps out I'm still good to go and the tables won't restrict my diving or make me sit out a dive. BTW I've never had a computer crap out on me although I've been with others who have. Also realize you have to dive with both. Having one sitting in your bag won't help.

jo8243
09-18-2007, 11:53
I carry them and sure, I can use them, but in reality, what's the point anymore? Computers have replaced them, just like the calculator replaced the abacus. I have two computers from different manufacturers. So I always have a backup and don't have to worry about a software bug screwing it up.

WV Diver
09-18-2007, 12:04
Dive table............that's a work bench for your scuba gear right?? :smiley20: :smilie39:

Well, at least I thought it was funny.

Honestly, in the real world (which could just me my own twisted reality) I mostly only deal with them when I am helping students, although I do refer back to my nitrox tables on occasion. I really use the planning mode on my computer for most dive planning, but even so I have enough experience with the tables to have a good idea in my head before I even go to the dive computer.

Working tables is not your most efficient way to dive as we all know. Seldom do we find ourselves doing square profiles. But if something happens to my computer, I have the tables around for back up and try to put dive info. down in my logbook as I go, so that the tables will be of use to me if something were to happen to the computer.

I can't recite them, but I think I could work any table whether I was trained on that particular table or not. They all basically work the same.

RonFrank
09-18-2007, 12:18
I carry my wheel, and the EANx tables in my log book. I ALSO carry two computers, and that is how I plan my dives.

If you are not using a wheel, and doing multi-profile dives, than your tables are short changing you in terms of NDL, or you are diving your computer.

If I spent the time to calculate multi-profile dives on the wheel before each dive, I'd still be on the boat half way into the dive! :smiley5: So I computer my dive plan, and dive my computer!

ertechsg
09-18-2007, 12:28
During open water we were during the deep dive we were last in the group to go down to the 100 ft mark stayed at 35ft for 20 -25 mins then followed the DM to 100 ft did what we did another 10-15 mins came back up was down 35min.. by tables 19 min at 100 ft my DM put me in a DECO DIVE OR KILLED ME certain stuff like chinacat said if you go by tables you sit out alot.

Vercingetorix
09-18-2007, 12:41
I've been trained on both NAUI (air) and PADI (air,nitrox)

RonFrank
09-18-2007, 12:42
During open water we were during the deep dive we were last in the group to go down to the 100 ft mark stayed at 35ft for 20 -25 mins then followed the DM to 100 ft did what we did another 10-15 mins came back up was down 35min.. by tables 19 min at 100 ft my DM put me in a DECO DIVE OR KILLED ME certain stuff like chinacat said if you go by tables you sit out alot.

Unfortunately PADI no longer teaches OW students with the wheel. That was, and I think still is with PADI advanced classes, the only way to plan a multi profile dive.

I'm a bit surprised that your instructor did not go over your dive plan in more detail. While I'll be the first to admit I dive my computer, I do generally do a reality check with the wheel if I think something we may plan could put me at risk.

What you are describing here however is a trust me dive. Your 100f dive at 19 minutes might have put you into deco. The max NDL with ZERO previous dives in the past few days is 25:00 minutes (Navy) or 20:00 minutes PADI. As you already had a bit of Nitrogen built up in your system from sitting at 35f, and you stayed at 100f for 19 minutes, you may have a deco obligation. If you did not meet your deco obligation (I have no way of knowing), they are put yourself at risk.

I don't do trust me dives. Had this been my instructor, I would at the minimum discuss this screwed up profile with him if not take it to the LDS owner for a review. This sounds dangerous to me, and likely more so for the instructor as I would assume he was at 100f longer than any of the students.

Vegas
09-18-2007, 12:53
I dive with a computer, but log my dives with the PADI tables when I can.

I will say this - when i went back to take my Nitrox cert, I was very glad I had kept in practice!

coralcrazed
09-18-2007, 12:54
is it really necessary to know the dive tables by heart??? I think everyone who dives should practice with them and get proficient on how to log single and double tank dives ect. but knowing it by heart, yah its nice but I don't think necessary, do you? If you feel yes than take it with you on your dive. thats all, who needs that tourture? get a computer! :)

RonFrank
09-18-2007, 13:00
is it really necessary to know the dive tables by heart??? I think everyone who dives should practice with them and get proficient on how to log single and double tank dives ect. but knowing it by heart, yah its nice but I don't think necessary, do you? If you feel yes than take it with you on your dive. thats all, who needs that tourture? get a computer! :)

I think folks need to know the tables well enough to do a sanity check. Of course we all know that computers never screw up, right! :smiley2:

If my computer indicated that I had one hour of NDL time at 100F the I would certainly stop diving that computer.

coralcrazed
09-18-2007, 15:27
is it really necessary to know the dive tables by heart??? I think everyone who dives should practice with them and get proficient on how to log single and double tank dives ect. but knowing it by heart, yah its nice but I don't think necessary, do you? If you feel yes than take it with you on your dive. thats all, who needs that tourture? get a computer! :)

I think folks need to know the tables well enough to do a sanity check. Of course we all know that computers never screw up, right! :smiley2:

If my computer indicated that I had one hour of NDL time at 100F the I would certainly stop diving that computer.
ok thats it I'm diving withmy tables from now on...:smiley29:

CompuDude
09-18-2007, 15:37
I have a general idea of what times are permitted at various depths, but I certainly don't have tables memorized. I know enough to sanity check the computer.

I can rock the PADI tables (and and nitrox) and the wheel. Never really spent any time with the tables from other agencies, however, so while I assume I could figure it out pretty quickly, I can't really say I know them.

For real diving, however, recreational multi-level dives are generally planned with my computer.

plot
09-18-2007, 17:08
i can do it if i try. most of my diving to date i havnt really needed too.

No Misses
09-18-2007, 17:17
I dive an AI DC. I tried to backup my DC with the tables on my first livaboard trip. At 5 dives per day (EAN 32), I quickly ran out of pressure groups to carry over. Maybe if I was doing the multilevel calculations I could have kept up. I still take the tables with me for contingency planning.

in_cavediver
09-18-2007, 21:41
I'm lazy and generally dive my computer (VR3 backed up with BT). That said, I know the limits/models well enough to get myself out of the water just guessing. I won't say I'd dive again that day but that would depend entirely on the profiles I've done. On serious dives, I usually plan a schedule and dive it. The computer is there as a sanity check and for unforeseen bailouts.

As for tables, well I know the RDP from my days DM'ing, the IANTD tables as well as numerous cut tables with Dplan, Jplan and GAP. Its gotten to the point that for shallow dives (<50ft) and less than 3-4 dives spread out in a day, I can pretty much dive without referencing a computer and still make the computer happy.

diverdad
09-18-2007, 22:21
I dive with a computer but i know my tables fairly well (not by heart). I'm looking into getting another computer for a back up just incase y2k decides to visit my primary.

BuzzGA
09-18-2007, 23:11
I have a computer but I still wear a watch and check the tables, its not that I don't trust the computer but my experience with all computers is they fail at some point so I keep the old fashioned tables on hand to keep myself (and my wife...who also has a computer but keeps a set of tables in her bag too) out of trouble

ScaredSilly
09-19-2007, 16:27
Before computers I had a simple algorithm for dives. My depth in feet and time in minutes when added together could not exceed 100 minutes. Now mind you this is for flat profiles but was a pretty reasonable rule for most reef dives.

crpntr133
09-19-2007, 22:38
I can actually do both NAUI and PADI but I voted for knowing the one that I was trained on. Can't recite them in my sleep.

Bill22
09-20-2007, 03:30
I dive my computer but have the Wheel for backup. Will most likely get an additional computer at some point.... but I think a dry suit and camera equipment will come first ;-)

DUnder
09-20-2007, 15:16
I don't know my tables by memory, but I can use the PADI Tables very well, as I do not own a computer yet.

Charles R
09-20-2007, 16:22
Getting ready for my Dive master So I know them all to well

divinginn
09-20-2007, 17:00
I use a computer now but for years i went by the 120 rule,depth plus minutes as long as you kept it under 120 total it worked out pretty well and was very easy to remember.

scubasavvy
09-20-2007, 17:39
I think I rely too much on the computer to tell me what's what. I do plan with a table though before every dive...

Buoyant1
09-24-2007, 11:22
I think tables are easy and fun! I had a blast during my Nitrox class with pressure group problems that our instructor gave us to practice!

I dive with a computer, but still check with tables to stay in practice