Is a Dive Computer necessary?

[Carter21]

Thank you so much in helping me make this decision everyone! I'm looking to buy Oceanic Geo 2.0 or Cressi Leonardo. Still can't decide between watch or console. Either way, will be renting or buying one for air.

 

[TSandM]

If you are going to rent your other equipment, a wrist gauge is easier to manage, because you don't have to install a hose on a rental regulator.

Almost all "tourist" (i.e. guided) diving is multi-level, and you may significantly impede other divers by diving tables, because of their inherent conservativism.

I would HIGHLY recommend purchasing your own computer, and then going through the manual so that you understand what all the displays mean. Knowing what the computer is telling you, for example, if you violate any limits, is much safer than misinterpreting it, or panicking because you don't understand what it's saying. In addition, many computers can be downloaded to a laptop, making dive logging very easy.

 

[eelnoraa]

Have a dive computer is not necessary, BUT knowing your depth and bottom dive is absolutely necessary. So you will need some device for that anyway. I guess one can get away from a dive watch and an depth gauge. If you are buying a depth gauge anyway, why not spend a little more for a computer.

---------- Post added August 31st, 2014 at 11:24 AM ----------

Can you drive a car without the speedometer? Yes. Should you? Can you fly a plane without altitude meter? Yes. Should you? Yes it is important to learn tables and I also agree that the first few dives need to be worked on the table but I would not say that we don't need a computer. I did the first few dives of my life without a computer and it was really hard to buddy up. Everyone on the boat was diving computers and it was hard to find a dive buddy who was on tables. When I did pair up with divers I was surfacing before them most of the time. Major PIA. So yes if you plan on doing this then you need a dive computer. Do a poll on scubaboard if you may. Ask all these guys who dive frequently, how many of them do not own a dive computer and I bet you you will be hard pressed to find anyone.

I don't agree with this analogy. To me, dive computer is like a navigation system in your car. It tells you where you should go given a set destination. A speedometer or altitude gauge of car/plane is like depth gauge and timer. They dont make decision or make estimation for you, but just display cruzial information. So yes, I will drive without a nav, but I won't dive without a speedometer.

I happen to be done that use gauge mode to dive. In fact, it may surprise you how many do NOT use computers.

 

[drrich2]

I'd add that if you own a computer, vs. renting, you will get used to the display. Yes, on a rental you can see depth, dive time elapsed and NDL. What more do you need?

Well, might not be a bad thing if you are used to that display for, oh, say, tissue nitrogen loading (I like this on Oceanics; gives me an idea of how nitrogen loaded I am theorized to be, so I can have some idea of how much I'm 'pushing it' beyond just being within NDL) and ascent rate monitor (to warn me if I go up too fast).

And after a dive, it's nice to know how to pull up the log & see your average depth, dive duration and max. depth. You probably won't be downloading dive profiles off a rental onto your desktop computer back home, either.

Richard.

 

[Craig66]

I find it interesting how many people believe that a dive computer is a piece of safety equipment. A dive computer is a piece of convenience equipment that allows you to multilevel dive and do multiple dives per day and does a good job of generalizing and estimating nitrogen exposure with the only trade off being a small LOSS of safety.

I certainly am not trying to climb on a soap box and but I am amazed that divers are not trained to use tables. Without learning tables I am not sure that divers will have a good understanding of the physics and physiology behind the calculations. To me that's a little like not teaching kids addition and subtraction because they have calculators.

Having a good understanding of tables helped me firstly recognize when my dive computer went wacky and after it went wacky tables allowed me to finish my dive day with albeit shorter dives.


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[dmoore19]

I suggest buying the computer too, then learning how to use it. I was only suggesting that if the OP was not going to buy one to find out what computer would be rented and learn how to use it.

 

[DiveNav]

...... Without learning tables I am not sure that divers will have a good understanding of the physics and physiology behind the calculations. ....

Really?
Being able to use a dive table doesn't necessary mean that a diver has a good understanding of the physics and physiology behind the calculations

 

[drrich2]

I certainly am not trying to climb on a soap box and but I am amazed that divers are not trained to use tables. Without learning tables I am not sure that divers will have a good understanding of the physics and physiology behind the calculations.

A lot of people who train with tables still don't have a good understanding of the physics and physiology behind the calculations.

Working with the tables and considering how pressure groups fall across a given surface interval time frame, or rise in a given time frame at a given depth, may give someone an idea that, for example, in theory you take on way more nitrogen faster at 100 feet than at 30, and seeing the NDL's for given depths on the table at a glance can be easier than figuring it out on a dive computer, so I don't regret learning tables nor did I throw mine away. I do like the tissue loading indicators on at least some dive computers that give me a crude visual indicator on how nitrogen loaded I'm getting on a dive, and how fast I'm dropping nitrogen when I get shallow or spend time above water.

But I dive computer all the way now. With your other example, even people who own calculators (most these days, since your smart phone's got an app. for that!) do basic arithmetic 'in their heads' from time to time. On the other hand, many divers can go for years (or the rest of their diving careers) without needing to use tables.

 

[boulderjohn]

I agree that learning to use a table in itself teaches very little about decompression theory. In an OW class, I teach decompression theory early in the class, explaining the theory part at an appropriate level for OW divers. They get a pretty good explanation then. Later in the class I teach them how to deal with the decompression issues I described earlier. If they are taking the table version of the class, I teach them how to use the tables. If they are taking the computer version (as just about all do now), I teach them to use the computer. The theory part is the same in either case.

 

[Craig66]

Really?
Being able to use a dive table doesn't necessary mean that a diver has a good understanding of the physics and physiology behind the calculations

No, understanding tables does not imply a deep understanding of dive physiology just like mastering addition does not mean you will join AP calculus. Nonetheless I still firmly believe that a diver trained on tables and square profiles will have a better understanding of nitrogen accumulation and decompression. More importantly it imparts the fact that the dive computer and it's alogarithms are not absolute and that at all times common sense should trump. Something that someone conversant with tables will best appreciate.




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---------- Post added August 31st, 2014 at 04:39 PM ----------

I guess we can argue back and forth whether teaching computers only is more about moving on with progress or rather represents dumbing down of scuba to make it more attractive for the masses.

For myself, when my daughter certified I insisted she learn tables and for her first 40 dives our dive plans involved a discussion on what she expected to see on her computer through the dive as based on her table planned dive. I firmly believe that she will be a better safer diver for it.


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