Are dive computers making bad divers?

[Steve_C]

If it does fail what do you fall back on. How do you tell time.

My other computer

how do you tell depth.

My other computer or the depth gauge on by console. (Computer is not consule)

get to the surface and end the day.

No, dive the other computer.

From personal observations. I have asked divers how long of a dive they can do in 30 ft of water. They have no idea. ?

more than a tank full at 30%

 

[AJ]

TThis is the problem with computers making bad divers. It has the diver turn their senses and dive over to a computer. If you maintain your ability to identify your surroundings then the computer is just a tool.

Computers don't make bad divers, tables don't make good divers. Understanding what you are doing makes good divers. Computers and tables are just tools, nothing more. Knowing what the numbers mean and understanding consequences of your decisions is what save diving is all about. Unfortunatly I have met very few divers that really understand decompression theory, what different gases and pressure do to your body and so on. Even many instructors don't know but claim all sorts off wisdom they don't have. Educate yourself and you will become a good diver, no mather what kind of instrument you use.

 

[Patoux01]

If you trust it not to fail then ok its your dive. If it does fail what do you fall back on. How do you tell time. how do you tell depth. This is the problem with computers making bad divers. It has the diver turn their senses and dive over to a computer.

That's a very funny one. Indeed, it's well known, all divers that use tables have 2 depth gauges and 2 timers, as well as 2 sets of tables in case a great white wanted to learn about navy tables, right?

 

[NAM001]

you are the only one ( I think) that caught what I was saying. For others the sarcasm was if an unplanning diver puts is sole reliability in a computer, then they have no back up. Most have been spoiled by the computer and have not used their senses because of the computer. IE how many could ascend at a safe rate with out the depth gage and a watch. The answers to the questions are moot because so many don't know a right or wrong answer , period, without a computer.

That's a very funny one. Indeed, it's well known, all divers that use tables have 2 depth gauges and 2 timers, as well as 2 sets of tables in case a great white wanted to learn about navy tables, right?

 

[CT-Rich]

Back when I learned the tables, there were rules that given to make the dive "safer" that were really based on nothing. Remember the old saw about do your deepest portion of the dive first? A lot of that was based on pretty shaky science. Computers include a lot into the calculation that wasn't available to us creating square profiles in 1980. I get much more reliable data from a computer than from a watch and depth gauge that I had to remember to set and then monitor all through the dive and during the surface interval. I agree with the others that the weak link is going to be the instruction, not the tool. Computers are awesome, but they are a tool, that when used appropriately, is awesome. Better data used for better situational awareness, makes the diving safer. My daughter is doing her OW (SSI) this spring and I am looking forward to seeing how training is done and what she is taught.

 

[Diving Dubai]

I like to use the analogy of Spell and Grammar check on computers. How many blindly use them (how many times have we all seen that typo in our posts) or forget the conventions and rules of grammar taught at school?

A tool is a tool, use it correctly and it will be of benefit Use it incorrectly and .....

 

[archer1960]

you are the only one ( I think) that caught what I was saying. For others the sarcasm was if an unplanning diver puts is sole reliability in a computer, then they have no back up. Most have been spoiled by the computer and have not used their senses because of the computer. IE how many could ascend at a safe rate with out the depth gage and a watch. The answers to the questions are moot because so many don't know a right or wrong answer , period, without a computer.

I dive with a wrist computer and compass on one wrist, but also carry a plain dive watch on the other wrist, and my console has a mechanical depth gauge and a compass as well. The only instrument I don't have a spare for is the SPG. It wasn't actually planned that way, but I discovered that I didn't like using my compass in the console, so bought a wrist compass, leaving the one in the console as a spare. I already had a 200m watch that I just used as a watch, so it became natural to use it when diving as a spare depth timer.

 

[DA Aquamaster]

Let’s not forget that many of the well-known divers of the 1960s through the 1980s also used decompression computers. Granted they were analog but did credit for multi-level dives.

Wasn't it that one they called the bend-o-matic?

Yep, but it worked surprisingly well. We all carefully monitored it compared to different tables for a sanity check though. If I recall correctly it tracked the French Navy tables closer than the US Navy tables, but close enough. The moniker was really not deserved. If it had, Scubapro (the importer in the US) would have been sued out of business.

The bend-o-matic used ambient pressure to push gas from one side of the unit to the other through a filter. It was in essence a single compartment model, with all the problems associated with that.

Did it work? "Surprisingly well" is a good answer, but that answer needs some context.

At the time, the most common dives being done were single tank dives using either a steel 72 or an AL80. In both cases, bending yourself on a single tank first dive of the day was virtually impossible provided you stayed above about 100 feet - unless you had a superb SAC rate or skip breathed. You simply ran out of gas before you on-gassed enough to get bent. If you did a truly multi-level dive, avoiding a square profile, doing the deepest part first and spending much of the dive at a shallower depth, it was hard to bend yourself with a single 72 or 80 even on a 110'-130' dive.

Which is to say, the question isn't whether the bend-o-matic worked "surprisingly well" but rather it worked better than no dive computer at all for a single tank diver. In that regard, I'll argue that the steel 72 was in fact the world first multi-level dive computer, provided you respected it's limits. Most divers in the era who understood US Navy tables, also understood the gas needed to bend yourself, and thus saw the multi-level advantage of a steel 72.

---------- Post added November 30th, 2015 at 09:14 AM ----------

I like to relate everything to flying, because that is my other hobby. The discussion of "old school" and new technology comes up in flying as well, the new pilots are to reliant on technology and the old guys won't pay attention to it the argument goes. In my personal opinion, if my radio goes dead, and my electronics go down, I better know how to pull out a nav chart, a wiz wheel, and a compass and be able to use them to get me home safe. In turn if I'm flying at night, or get into a cloud I need to trust my instruments to tell me how to fix it. Basically, knowing both systems, and being able to use them in unison, can make things safer.

I do the same thing, in part because aviation is light years ahead of diving when it comes to accident analysis and feeding the results back into practice.

I learned to fly in a 1956 Supercub with airspeed, altimeter, tachometer, oil pressure and a whiskey compass. For radios it had a Narco Mk III radio that even worked on rare occasions if the range was short and you didn't mind a lot of static. I learned how to actually fly in that aircraft and I learned how to navigate by pilotage and dead reckoning.

My instrument training occurred in a Cessna 172 with a basic six pack no bells and whistles panel. While I later enjoyed flying instruments in aircraft equipped with HSIs, flight directors and moving map displays, I never forgot the basics of flying instruments on a basic panel, and on a partial panel. I also enjoyed watching pilots who were not so diligent in maintaining those skills struggle when I took away the GPS and moving map display, the flight director or HSI. That suddenly put them in the positon of having to develop and maintain a mental map of where they are relative to the runway and nav aides in addition to keeping the airplane right side up, on course and on glideslope during the approach.

-----

I think the relevance to and harm of computers in recreational diving is minimal, given a single tank, the benefits of nitrox and reasonable depths. Ideally the diver should understand what's happening a lot more than they do, but it's hard to teach that in the weekend courses that have become all to common. It's also not a skill that is likely to develop later in a dive travel industry that revolves around DMs serving as in water nannies to OW divers.

Weekend dive courses and overreliance on DMs to handle dive planning, bottom time, etc, are far larger contributors to the "bad diver" syndrome in recreational diving today than the use of computers.

However once you get into more advanced or technical diving, the diver's knowledge does need to develop to prevent them from becoming over reliant on the computer, and even more importantly to understand the interplay between decompression planning and gas planning, as well as the planning skills needed to develop contingency plans for delays, lost gas scenarios and computer failure.

 

[Akimbo]

... Did it work? "Surprisingly well" is a good answer, but that answer needs some context. ...

The context of a single 72 is inconsistent with my observations in Northern California during the 1960s. These things were expensive and bulky so very few divers purchased one that dove one or two single 72s/day. Most, if not all, got them for decompression diving with doubles. Most divers I knew were photographers and traveled to warm water sites and needed to make the most of their bottom times.

One of the dive shop owners in San Francisco acquired an ancient riveted single-lock decompression chamber to use in his Scuba classes and to test camera housings he built. He had a SOS decompression meter in the chamber on most runs to check against tables. His conclusion was, if my memory serves, was it was less conservative than the US Navy tables on the first dive but a little more conservative repeds. He felt that they were closer to the French Navy tables of the day, which makes sense given the meter was made in Italy.

The thing that made it so surprising was that such a simple porous material could mimic decompression tables so closely. Tables were first calculated using slide rules and based on several tissues. They were then "tweaked" as DCS data was collected from chamber tests at EDU and fleet operations. Finding a porous material that approximated the non-linear characteristics of tables must have required a lot of experimenting and testing.

 

[DA Aquamaster]

One of the dive shop owners in San Francisco acquired an ancient riveted single-lock decompression chamber to use in his Scuba classes and to test camera housings he built. He had a SOS decompression meter in the chamber on most runs to check against tables. His conclusion was, if my memory serves, was it was less conservative than the US Navy tables on the first dive but a little more conservative repeds. He felt that they were closer to the French Navy tables of the day, which makes sense given the meter was made in Italy.

The thing that made it so surprising was that such a simple porous material could mimic decompression tables so closely. Tables were first calculated using slide rules and based on several tissues. They were then “tweaked” as DCS data was collected from chamber tests at EDU and fleet operations. Finding a porous material that approximated the non-linear characteristics of tables must have required a lot of experimenting and testing.

I would hope that the bend-o-matic was more conservative than the US Navy Tables on repetitive dives. When dove to a square profile the USN repetitive dive tables of the era had a 4% hit rate using Navy divers. That made perfect sense for the US Navy as a) they didn't normally do open circuit decompression dives, b) if they did, it was with a recompression chamber on board, and c) if a chamber was not on board and decompression diving operations were taking place it was based on operational necessity in circumstances where the safety of the diver was secondary to the safety of the crew, another vessel, etc.

The US Navy tables were never intended for recreational decompression diving, and they worked for that purpose only to the extent that you added fudge factors in the form of avoiding square profiles, rounding to the next deepest depth and next longer time, and stepping up to the next deepest depth or time on a cold water dive or hard working dive, and using next deepest depth and time on a cold, strenuous dive.

In fact, the bend-o-matic needed to be a lot more conservative as like a modern dive computer, every profile was a square profile with no fudge factors available. That's an element that I suspect some computer only divers may not realize, and it's the reason multi-level dive tables have shorter max bottom times at any given depth. The saving grace for students who are not aware of that, is that dive tables today are much more conservative than the old US Navy tables.