Are dive computers making bad divers?

[scubaozy]

Kind of a funny way to bring a 6-year-old thread back from the dead, because dive computers are both more accurate than dive tables, and they are more precise than diver tables. Accuracy and precision - Wikipedia

They measure your depth in typical increments of 0.1ft/0.1m versus of 10ft/3m for tables, and typical increments of time of 1-5 seconds instead of 60 seconds for tables. Dive watches make measurements of similar precision, of course, but the tables themselves are about an order of magnitude less precise than computers.

And for multi-level dive profiles (that is, anything besides a perfect square), they will also measure your depth over time more accurately. Even for square profiles, the accuracy captured by the dive computer is a little better as well, due to their improved precision.

Dive tables are based on statistical data and same half times are used in computers, you use the dive computer not to get DCS, statistically, you will not be having less probability of bends, but you will be able to dive longer with the same risk. Both computers and tables are low accuracy. Provided you use a digital bottom timer and dive a square profile, you can get pretty precise with a table as well.

 

[Scraps]

Dive computers are but one of many examples of devices that allow people to perform tasks or obtain needed information without learning tedious manual processes.

The more reliable the replacement system and the less severe the consequence of losing the replacement system, the less we should lament thst the old ways are forgot.

Dive computers are in a different category. They replace a manual system that was most notable for not being used by the majority of recreational divers who should have been using it.

I have never—not even once—seen a recreational diver pull out a dive table on any boat I dove from or worked on unless the diver was participating in a class.

Nearly all tourist divers without their own computers simply trust the divemaster not to let
them get into trouble. If their rental gear includes a computer, most tourists don’t bother learning how to use it.

Omce, early in my diving journey, before I understood why computers allow more bottom time and shorter surface intervals than the tables, I dutifully consulted my tables on a vacation dive outing and grew concerned that my divemaster was leading us into harm’s way. When I tried to compare my findings with the other customers on the boat, none could offer any information or insight from tables or their computers. The DM assured me all was well but didn’t explain why.

I don’t think that level of near-universal cluelessness was uncommon.

For this reason, I consider the wider availability of easier-to-use dive computers to be an almost unmitigated good. It makes available information that divers should have had but didn’t bother to obtain for themselves.

I’m a lot more worried about boaters with no piloting skills who might lose GPS data than I am about recreational divers whose computer batteries might fail. The latter can at least find their way to the surface when they notice the blank screen.

 

[GDHLEWIS]

Still use tables to do a rough dive plan as I was taught with tables and did dive with tables back in the day. I always have a set of tables in my dive kit just in case the computer dies on me I can still dive.

 

[rongoodman]

Does anybody think tables would have ever been a thing had dive computers been available from the beginning with the computing power to generate NDL times and deco profiles on the fly as they do now? They were the only way to summarize and present this information at the time and divers learned to deal with the compromises required, but they don't bring anything extra to the table just because of the way that information is presented on a sheet of paper. The best thing you can say for them is that they encourage some semblance of pre-planning the dives made using them.

 

[Jcp2]

Does anybody think tables would have ever been a thing had dive computers been available from the beginning with the computing power to generate NDL times and deco profiles on the fly as they do now? They were the only way to summarize and present this information at the time and divers learned to deal with the compromises required, but they don't bring anything extra to the table just because of the way that information is presented on a sheet of paper. The best thing you can say for them is that they encourage at least some semblance of pre-planning the dives made using them.

Showing a diver the usefulness of the plan mode on my Leonardo during the surface interval is always fun. The first response is usually “how did you do that?” followed by “does my Garmin do that too?”

 

[boulderjohn]

Still use tables to do a rough dive plan as I was taught with tables and did dive with tables back in the day. I always have a set of tables in my dive kit just in case the computer dies on me I can still dive.

So how do tables allow you to continue to dive in case your computer dies on you? By "how," I mean what exact steps do you use? I just completed five days of 2-tank dives. I will pick out one of them and give you the information from the first dive that you would need to use the tables. You tell me exactly how I would use tables to prepare for the second.

First Dive: Using EANx 32, we went to 103 feet for a total dive time of 81 minutes.
Surface Interval: 1:15
Second Dive: Using your dive tables, tell me how deep I can go and for how long.

I will tell you that using our computers, our second dive was to a maximum depth of 82 feet, and we dived for 88 minutes.

 

[OMyMyOHellYes]

I know. Computer trained divers are weak and lazy and probably think pineapple is a legit pizza topping.

You see the same in aviation all the time....

Instrument panel from dive table days that "REAL" pilots would use in heavy IFR conditions:

No way that a "REAL" pilot would use one like the weak, bad pilots trained in modern aircraft and systems from the dive computer era (note that Garmin makes the panel below just like the Descent computer line):

(Don't get me wrong. I LOVES me some BE-18, but in heavy WX and needing to get somewhere better, faster, more reliably, BE-300/350 might work a little better)

Learning dive tables is a great way to improve understanding of the practical application of dive practices - even with a computer. And makes one very very thankful the computers came along....

OMMOHY

 

[Wibble]

Still use tables to do a rough dive plan as I was taught with tables and did dive with tables back in the day. I always have a set of tables in my dive kit just in case the computer dies on me I can still dive.

After a while you memorise certain depth/length traits. Like 20mins on air at 30m/100ft. Or 1:1 around 45m/150ft (for every hour you're at 45m you'll need 1h on deco).

For my first 3 dives after ANDP I used a slate with the dive plans, basic, +3m/10ft, +5 mins and +3m/10ft+5mins. Then gave up as the computer's so much easier to use and doesn't rely on memory.

As the computer's now essential, need two of them.

Tables are great for visualising and understanding the relationship of depth and time. Then there's MultiDeco and a couple of Shearwaters for simplicity.

 

[Guille G]

So how do tables allow you to continue to dive in case your computer dies on you? By "how," I mean what exact step do you use? I just completed five days of 2-tank dives. I will pick out one of them and give you the information from the first dive that you would need to use the tables. You tell me exactly how I would use tables to prepare for the second.

First Dive: Using EANx 32, we went to 103 feet for a total dive time of 81 minutes.
Surface Interval: 1:15
Second Dive: Using your dive tables, tell me how deep I can go and for how long.

I will tell you that using our computers, our second dive was to a maximum depth of 82 feet, and we dived for 88 minutes.

PADI metric dive tables say that you were dead after 20 minutes at that depth. 30, if we break protocol and round your depth down instead of up.

You, sir, may be a scuba zombie.

 

[boulderjohn]

PADI metric dive tables say that you were dead after 20 minutes at that depth. 30, if we break protocol and round your depth down instead of up.

You, sir, may be a scuba zombie.

That was my reaction on my very first dive in Cozumel, about a quarter century ago, when I was there as a newly minted diver. After the first dive, I whipped out my log book and tables and began the calculations to prepare for the second dive, as I had only recently learned in my OW class. I stared at the numbers in disbelief for a while, thinking exactly what you said--"I'm supposed to be dead!"

I looked up and saw that all the other divers were looking at me with bemused grins. One of them pointed to my tables and said, "It makes a decent Frisbee." I bought a computer as soon as I got home.

That marks the one and only time I have ever seen a diver produce tables to attempt to plan a recreational dive outside of instruction.