Reasons NOT to Use a Computer for a New Diver?

[Aguablanco1]

When I was in machinist training I was told I had to learn trig the hard way without a calculator. The reason was that the calculator could lose power or break and then where would I be? My answer was, why not have two calculators and be prepared. I see no valid reason to forgo technology because it might fail. Don't SPG's fail? Don't all mechanical and electronic gear fail eventually? How about watches? Anything can fail, the issue is to be prepared for the failure. I have 2 computers on every dive. Maybe a little pricey but certainly not overkill. Why be a Luddite? Use the technology and understand it's shortcomings.

The earlier response about the dive leader not allowing computers on "his" dives is a very dangerous situation. Who is he to tell me what I consider safe and necessary in any of my selected gear. As long as it is in good repair and functional, it is none of his business how I dive.
RichH

 

[lindenbruce]

I can't find a good reason not to either. However, several have made good points about getting to know the tables and learning how to use them. But here is something too, which several posters came close to saying, but it didn't come out that way even if they were thinking it.

And this is going to be dark folks so if you are squeamish stop reading for a minute okay. But, post dive accident analysis. Computers can aid in investigating dive accidents and incidents. They can even help doctors in determining severity of DCS and applying the computer data to re-compression treatments. If you dive tables there is little to no data to tell anyone your dive profile. Sure they maybe a bottom timer and a depth gauge, but those only give a small sample of the actual dive profile. They don't tell anyone how long you stayed at XYZ depth etc. etc. So, I think computers have WAY more going for them than running tables. B.

 

[clownfishsydney]

I am constantly amazed by people who claim that divers should not use computers. When I started diving in 1988 computers were extremely rare. I dived for three years before I purchased a Uwatec Aladin Pro in 1991. It is more conservative (I still have one and use it as a back up on trips) than most dive tables. Since then I have never done a dive without one unless I have forgotten my computer.

I agree that it is essential that people know how it works and what it means. I also disagree that the Shearwater manual is good, it is sh*t (my wife has one). Most, if not all manuals I have ever seen are terrible in explaining how they work. Most need many dives before you understand them.

I never use tables. I have no need to. Why? I know to the minute what my NDL will be for every dive I do in Sydney. Elsewhere, for most dives if I know the expected depth I can use my knowledge of Sydney dives to work it out. For other multi-level dives, I do not need to know as I will constantly review the computer and know how deep I can go and stay. Multi level diving is easy if you monitor the computer.

 

[The Chairman]

I am very pro PDC for the new diver. I tell them to buy a PDC as soon as they can. I have seen a lot of narced and confused divers. I've never seen a narced or confused PDC. Oh, I've seen them fail and have had to install new batteries. That's OK. Call the dive or go to your back up.

 

[Hawkwood]

.... Don't SPG's fail? ...
RichH

That is the only piece of equipment I have had fail during a dive. It flooded.

 

[boulderjohn]

That is the only piece of equipment I have had fail during a dive. It flooded.

I have a pretty expensive dive watch that I use when instructing in the pool. There are exercises students must do that are timed. In my last class (last week), I glanced at the watch to see where the second hand was at the beginning of the exercise, and then about 20 seconds later glanced at it again. I was surprised that the second hand had only moved about 10 seconds. Then I realized it was not moving at all. I ended the exercise when I judged 30 seconds had passed. We were in the shallow end of the pool, and when we stood up, I looked at the watch to try to see why it had stopped. It was running. It had stopped for a little over a minute. I have no idea why, and if I had not coincidentally looked at it when it happened to stop, I would not have known it had happened at all. The same thing happened to me during a pool exercise several years ago. When I timed students for their float at the beginning the session, my watch was precisely the same as the clock on the wall. Near the end of the session, it was 5 minutes slow. I don't know when it lost those 5 minutes. This was a different watch, so I have had two different dive watches stop and then restart while I was using them under water. Luckily it was in a pool, where it had no serious effect. If I were timing my dive and my planned ascent with it, things could have been very serious.

I think any piece of equipment can fail during a dive, and it seems to me that a dive watch that stops and starts without any way of you knowing about it unless you happened to be looking at it when it happened is a pretty serious failure for those depending upon it being accurate.

 

[TMHeimer]

I had my watch flood once because a loose string from my shell bag got caught on the button to move the hands and pulled it out (what are the chances?). So you just end the dive unless you've been down only 10 minutes at 30 feet.

 

[Eric Sedletzky]

I am very pro PDC for the new diver. I tell them to buy a PDC as soon as they can. I have seen a lot of narced and confused divers. I've never seen a narced or confused PDC. Oh, I've seen them fail and have had to install new batteries. That's OK. Call the dive or go to your back up.

I have not only seen narced and confused divers but I've also seen bottom timers fail just like computers.
So now there are two problems.

 

[boulderjohn]

I had my watch flood once because a loose string from my shell bag got caught on the button to move the hands and pulled it out (what are the chances?). So you just end the dive unless you've been down only 10 minutes at 30 feet.

That's because you can see the results of a watch flood easily and can make that decision. The same would be true of a computer that stops working during a dive. There is therefore no difference.

On the other hand, if a watch stops running for 5 minutes during your dive to 100 feet and then starts again, you won't notice it. You will just add 5 minutes to your bottom time without knowing you did it.

 

[Diver0001]

I think any piece of equipment can fail during a dive, and it seems to me that a dive watch that stops and starts without any way of you knowing about it unless you happened to be looking at it when it happened is a pretty serious failure for those depending upon it being accurate.

I've had a number of citizen watches fail over the years and had one stolen. After getting tired of spending a bunch of money on dive watches I bought a €30 Casio that's water tight to 200m and has a 10 year battery. I've had it for about 3 years and I'd highly recommend it. The whole cost of this watch is about 1/2 of what it takes to get a citizen battery changed and... the best part... it works as advertised!

After all the discussion about computers being too expensive, I can safely say that I've personally spent more on dive watches than I have on computers in the time I've been diving.

R..