Are dive computers making bad divers?

[miketsp]

It is becoming more and more frequent that I find myself with divers who are extremely computer dependent. Since computers are becoming a dime a dozen, I am not sure if this is a bad thing. I asked one of the divers I was with if she was able to plan and conduct dives without a computer and she told me that she has over 200 dives but was never trained on tables.

How many of you guys do dives without computers? For those senior divers who have been diving since before the computer revolution, do you feel that the new generation has been idiotized by computers, or no.

How many engineers do you know that still use slide-rules?
- A slide-rule is much more reliable than a calculator or a computer or a smart-phone. It will NEVER let you down.
- It makes you think about what you doing.
- It gives you a feel for the numbers.
- It looks cool.

Yeah, right! I gave up my slide-rule a long, long time ago when better tools came along.
Most of my dive trips are expensive and I want to maximize time UW, so Nitrox and a dive computer are the best tools for the job.
It doesn't mean I stopped thinking.

 

[The Chairman]

The DIR folks have a much more diciplined diving regiment. Including carefully reaserched gases that act similar and there for does not need a computer to figure out the deco.

You're confusing phobias and psuedo science for being 'disciplined'. There's little actual research into which gasses to use. The high priests have so ordained it and everyobne scrambles trying to justify it.

 

[scubadada]

How many engineers do you know that still use slide-rules?
- A slide-rule is much more reliable than a calculator or a computer or a smart-phone. It will NEVER let you down.
- It makes you think about what you doing.
- It gives you a feel for the numbers.
- It looks cool.

Yeah, right! I gave up my slide-rule a long, long time ago when better tools came along.
Most of my dive trips are expensive and I want to maximize time UW, so Nitrox and a dive computer are the best tools for the job.
It doesn't mean I stopped thinking.

I haven't used a slide rule since 1972 freshman physics, my 1st calculator, that did the advanced function of square root, cost $100 that same year
I've been exclusively using a dive computer and diving nitrox since 2002. I occasionally look at my tables, I frequently use MultiDeco

 

[NAM001]

My point was not that they were the best gasses for diving cause they don't really comply for any best gas process. they are the best 3 gasses for using ratio deco that are used over a great depth range, with each gas to their own depth band. As such using them makes it easy to do the ratio deco and no longer need the reliance upon computers. The dicipline in DIR is based on use of those gasses. With out that they would be hosed. I have recently seen an article using ratio deco in recreational diving based on ean32 as a standard gas.

You're confusing phobias and psuedo science for being 'disciplined'. There's little actual research into which gasses to use. The high priests have so ordained it and everyobne scrambles trying to justify it.

 

[Neilwood]

I would actually do that myself. If the computer was on the first dive and reasonably close? Why not use it? Just stick to your buddy.

If five minutes makes the difference between getting bent or not, you're diving way too close to the NDL. If you don't feel good about your decision, then don't do it. My earliest diving saw me use a red ribbon as a depth gauge and I didn't even know tables existed. My dives were never that deep and I only owned the one tank. My surface interval was the time it took to get that tank filled. Stop trying to set unreasonable goals for yourself and you probably won't get hurt.

However, I must point out that the most common PDC error is the battery. Carry an extra one or more with you. I'm here in Curacao, with two PDCs, two senders and 4 batteries. I can probably buy the batteries I need here, but I avoid the hassle by bringing my own. Then the guy with the dead PDC can probably just pop in another battery and dive normal. No probalem, mang!

I know its bad of me to admit it but my first post cert dive was on someone else's PDC (the company that had organised the weekend trip had a major issue with a ferry company leading to the van not being allowed to cross to the dive site with most of the gear on board including all the dive computers).

In my defence it was a shore dive to approx 18m (with an approximately square route meaning I was going from about 5m at the start to 18 for the second leg, reducing to 5 on the third leg and the return to the start point). With my air consumption NDL was never going to become an issue (I am lucky if I make it to 30 mins on a 12L filled to 230bar) and I would be offgassing on a large portion of the dive at "safety stop" level. Add to that the fact that it was the only dive that day and I was sticking to my buddy like glue, I can guarantee that my profile was within 0.5m of his at all times.

 

[EFX]

.....me: well then, just use a dive watch and tables.......

And how do you measure your depth?

No measurements needed. We know the max depth is 50 feet (15 m).

 

[leadduck]

Nice responses guys. Id also like to hear from the DIR/GUE crowd why they find it necessary to shun the use of computers.

I'm not from the DIR/GUE crowd, but AFAIK, tech divers use decompression software a lot for planning their dives -- on a desktop PC. They use multiple gases, bottom mix, have long deco times, ... you don't plan that ad hoc on a wrist watch. The dive including bailout strategies is calculated in detail with software such as V-Planner, is agreed upon in the team, gases are ordered, the plan is written on wet notes. During the dive, you use redundant depth gauges and timers. Some dive computers have the "gauge mode" for that purpose, to switch off all deco computation. There's no advantage from using tables here either, although the strategy is similar: plan the dive ahead, then dive the plan.

I think the typical application for dive computers is repetitive recreational diving, where the computer keeps track of individual nitrogen loading over multiple days, and you still can plan the dives by experience and mental arithmetic. And yes, many give in to temptation of not planning at all but do kind of rule based diving. Where's the limit when most divers stop using the wrist watch dive computer and plan it on a PC instead? My gut feeling is once they aim for more than 20min deco time, use helium or use more than one deco gas.

 

[boulderjohn]

Im probably not the person you actually want to try to answer this, but i am going to try. Computers are another thing to fail. Hit something and break it, leaky batttery oring at 200 ft, who knows. The DIR folks have a much more diciplined diving regiment. Including carefully reaserched gases that act similar and there for does not need a computer to figure out the deco.

So instead of a computer that can fail they typically use a Uwatec bottom timer, which is just a computer with less functionality, or they use a computer in gauge mode. They may even use a watch, and the only instrument that I have ever had fail me on a dive was a watch.

As for the carefully research gases--BS. The were in South Florida, where many dive shops bank EANx 32. The easiest and cheapest way to make trimix in that situation is to make the GUE/DIR standard gases--put in the percentage of helium you want and then top it off with banked EANx 32. That also allows you to switch from one standard gas to another in a partially used tank--the only math you need to do is figure out how much more helium to add before topping off with EANx 32, and that's elementary school arithmetic.

My point was not that they were the best gasses for diving cause they don't really comply for any best gas process. they are the best 3 gasses for using ratio deco that are used over a great depth range, with each gas to their own depth band. As such using them makes it easy to do the ratio deco and no longer need the reliance upon computers. The dicipline in DIR is based on use of those gasses. With out that they would be hosed.

The gases were not chosen to match ratio deco; ratio deco was created to match those gases. They were using those gases for the reason stated above, and they were planning using a desktop software program. They wanted a way to be able to make changes on the fly, and they developed an arithmetical process to recreate what they were doing with those gases within a range of dives.

I have two sources for what I wrote. One is Andrew Georgitsis, who was directly involved with this when he was the training director for GUE and later the owner of UTD, where I did my early technical training. The other is Jarrod Jablonski, owner of GUE, with whom I communicated directly as I tried to understand the very different ways that GUE and UTD use ratio deco today.

 

[kensuf]

Nice responses guys. Id also like to hear from the DIR/GUE crowd why they find it necessary to shun the use of computers.

The times are changing. Several GUE type guys I know dive with computers and even use, gasp, electronic closed circuit rebreathers. I think I even saw PfcAJ diving a Shearwater this weekend.

However, just because some of them now have a computer strapped to their wrist, that does not mean they have stopped properly planning their dives. In the DIR mindset, you have your dive well planned before you get in the water. Part of that planning includes having a set of tables that are cut for the planned depth and time, plus a few contingency depths/times, and you should also understand how the tables are formulated so that in the event that your dive drastically deviates from the plan, you can adjust them as needed. In true DIR fashion, you should have a pretty solid understanding of how long your dive will be before you ever get wet.

BTW -- most of us have the most powerful pattern matching computer ever created right between our ears. If you cut several different deco schedules for various bottom times at various depths, you will probably begin to recognize a pattern that would allow you to extrapolate the next few series in the event that you run over (or under) your planned schedule.

Now.. Some of the DIR reasons for not using a computer include:

1. A bottom timer and multi-deco are a fraction of the cost of a Shearwater Petrel (or seabear).
2. Blindly following a computer can lead to laziness in dive planning.
3. A computer doesn't know how hard you were working, or if you got cold on the dive. So it is possible that the computer will tell you that it's safe to go up when you need to stay in the water a bit more -- your brain can adjust your schedule accordingly.

Please note, I do not consider myself part of the DIR crowd (I dive a rebreather and use sidemount bailout), and I have never taken a GUE course. But for years I used to use just a bottom timer and tables.

 

[2airishuman]

I don't see how you can learn to plan dives and internalize an understanding of the relationships among depth, no-stop time, and surface intervals without tables. If I only had a computer I'd run a bunch of scenarios, write down the results, and make tables. I don't see how anyone can make an informed choice on whether it's worth pursuing Nitrox certification, or using Nitrox for any one particular dive, without tables or, again, running a bunch of scenarios on a computer and making up some tables. Same thing applies to deco dives and accelerated decompression.

I suspect that a large share of divers never really understand any of this, in many cases because they lack the aptitude for it. They dive anyway. Is it better that they dive with a computer?

The underlying question is one of how much understanding is required to dive safely. Do you need to be able to derive the gas laws from F=ma? Do you need to be able explain the limitations of Dalton's law in that context and demonstrate them in the lab? How much anatomy and physiology do you need to know to truly understand DCS?

For many dive profiles, most people can dive more safely with a computer than without one, because the opportunity for error is reduced. The safety improvement becomes more marked when the diver's skills are weak. Divers with poor aptitude for dive theory may never gain enough understanding to be able to use dive tables properly no matter the quantity or quality of instruction they receive. Using a computer allows these people to dive with a degree of safety not otherwise possible for them.

Whether they should be diving at all is another question. But it's one that puts is in the realm of making people's choices for them, just as we would if setting high standards for strength, endurance, medical fitness, independent swimming ability, etc.