Dive Tables VS Dive Computer

[oly5050user]

Hi! I'm a very new diver, I just completed my open water this past summer and I have only been out twice since. In my training, we weren't really taught how to monitor our own nitrogen levels (we learned about it in theory, but just relied on the DM's computer while in the water) so I'm a bit confused now that it is actually up to me. Many people talk about how using the dive tables is a basic and cheaper option, but (forgive me that this sounds very dumb, I know) doesn't that mean you need a dive watch? The only ones I have been able to find are nearly as expensive as a dive computer, so then why would anyone encourage learning "the basics" and diving with the eRDPml or tables? Not sure if I'm missing something here... and we were never encouraged to go out and buy a dive watch so what are they expecting that we do?

I explain the RDP table from a historical perspective. Do not really teach it , only show how it was used. Why spend time on something you can spend an hour teaching and they never use, or even remember how to use in less than a week? Then I show a computer and explain you will never see a table in use on a boat. You need a watch and depth gauge to use table. A computer cost less. Buy a computer.

 

[loosenit2]

I explain the RDP table from a historical perspective. Do not really teach it , only show how it was used. Why spend time on something you can spend an hour teaching and they never use, or even remember how to use in less than a week? Then I show a computer and explain you will never see a table in use on a boat. You need a watch and depth gauge to use table. A computer cost less. Buy a computer.

I have a Shearwater dive computer and I still use dive tables for every dive. I find them an easy and effective tool for planning dives. If all you do is teach folks to go down and come up when the computer starts beeping at them you are building very bad habits.

Computers are just calculating the tables in real time with more exacting increments, the table is not obsolete.

 

[kelemvor]

Hi! I'm a very new diver, I just completed my open water this past summer and I have only been out twice since. In my training, we weren't really taught how to monitor our own nitrogen levels (we learned about it in theory, but just relied on the DM's computer while in the water) so I'm a bit confused now that it is actually up to me. Many people talk about how using the dive tables is a basic and cheaper option, but (forgive me that this sounds very dumb, I know) doesn't that mean you need a dive watch? The only ones I have been able to find are nearly as expensive as a dive computer, so then why would anyone encourage learning "the basics" and diving with the eRDPml or tables? Not sure if I'm missing something here... and we were never encouraged to go out and buy a dive watch so what are they expecting that we do?

Sounds like your instructor didn't follow agency standards. Every agency I know of requires you to plan a dive and dive that plan in order to be certified. At least you're aware of the problem and are trying to do the right thing in order to keep yourself safe now. In general, dive safety is up to the divers themselves. Professionals usually try to help you out, but it's still your responsibility - and you're handling it correctly so far!

Like @loosenit2 said, you can use a cheap casio watch. I could have sworn I saw people saying they got it for $20ish dollars. The only real "problem" with tables is that you'll get far less time underwater than a dive computer will give you. This is because the DC calculates your data repeatedly, rather than just using "average" depth.

I think what most people in your situation do is to rent equipment. Most dive shops and dive boat operations have gear available for rent. Most of those rental setups will include a dive computer of some sort. In fact, some dive boat operations require a computer. The boats I've been on that required a computer also provided one free of charge to anyone who needed it. In my experience, $50 or less will get you pretty much everything you need for a day of diving. I rented gear for the first year after I was certified. Then I gradually bought stuff until I had everything I needed.

If you're not yet confident (and given your training, it seems unlikely that you would be) you might consider hiring a divemaster to dive with you the first couple times you go out after class. It's not at all uncommon and nothing to be embarrassed about or anything like that. Some boat operations put a divemaster in with each group of divers no matter what.

 

[tursiops]

This is because the DC calculates your data repeatedly, rather than just using "average" depth.

I think you mean "maximum" rather than "average."

 

[arcticat99]

another thing about a computer.if you are going to get your own regulator you will need a depth gauge .and a entry level computer is only costs a little more than a depth gauge and the computer does that as well .living on the west coast you should be able to find a good used for a decent price

 

[Caveeagle]

I will probably always believe that a basic understanding of simple dive tables is a good idea. Even if it’s just to reinforce how a computer works to calculate NDLs and surface intervals.

Computers are a major step forward and should be a part of every OW class, as well as Nitrox (in my opinion this knowledge is more useful to the average new diver than a snorkel)

I think it’s a good idea to find out what most of your potential dive buddies are using. Getting a decent computer with Nitrox capability Is one of the first pieces of gear I would buy. I don’t like renting, because some screens are busy and confusing.

 

[kelemvor]

I think you mean "maximum" rather than "average."

Apparently, it's a perishable skill that I haven't used in about 5 years . I need coffee. Error ID: 10t. <insert other excuse here>

 

[Vallonen]

If all you do is teach folks to go down and come up when the comptuer starts beeping at them you are building very bad habits.

@Rosevb
Learn how to use a dive table. You build from the ground up.

Do not cut corners.

 

[SandyRobinson]

There is a lot of value in using tables as a beginner. They are simple to use and as alluded to earlier can give the new diver continued/additional reinforcement of depth and time for NDL diving. A depth gauge and a Casio watch are inexpensive. Use them for a few dives with the tables. You probably will have had a chance to learn a little more about computers, their features, and what is best for you. After you buy a computer, your depth gauge and watch are a backup - unless you decide to buy two computers

YMMV but I was always told to buy a 200m watch, not because I would ever dive that deep but that additional pressure could be put on a watch by arm movement or your watch hitting something - should not be hitting anything but it happens. An analog watch with a unidirectional bezel would be good.

Good luck.

 

[CAPTAIN SINBAD]

Hi Rosevb,

When a person who has PAID her money to learn and get certified in how to dive, comes on an internet forum and asks this question then it reflects the pathetic state of scuba education being given to recreational divers. I too have come out of scuba diving courses wondering exactly the same thing. Now that I am certified, how do I really do what I am certified to do? The question is not whether you should dive with a computer or without one. People can have their opinions on it and there is no right and wrong answer. The real question is that as a certified diver, we should be able to determine that for ourselves.

When we are teaching a new student basic arithmetic, (2+2 = 4) are we training them to do that on calculators from day 1? I do not know of any school that teaches basic math by handing students calculators. It will reduce the time schools spend on each student considerably but we are still teaching numbers then basic 2 -3 digit math. Speech software is turning spoken word into written letters. We are still teaching words and alphabets. Scuba industry unlike public schools is profit driven, therefore basic common sense that applies to all academic scenarios is abandoned so that gadgets could be sold. You will never see commercial diving schools or military diving academies training divers on computers from the first day even though they are training professional divers. They all start out on tables and every diver diving in professional capacity is able to conduct their dives using tables.

By using tables for the first few dives, a student has demonstrated that she has the understanding of what is happening inside a computer. If computers were taken away from divers today and they were asked, "Do you understand what is happening inside this gadget? Can you show me?" A person who knows that is happening inside the computer will be able to take NDL limits, how they turn into repetitive dive groups and be able to show you what a computer is actually doing. You can be sure that now this person understands decompression. There are so many divers who will not be able to show you what is a computer doing on some of the most basic dives and yet in their own minds they are convinced that they understand how decompression works?

When we create a culture of starting people out on dive computers from the very first day then we end up creating a very large community of grocery shoppers who will go to the grocery store with a 10 dollar bill, pick up 4 soda cans of .99 cents each and then pull out their cell phones and add this up to know if they can afford the purchase or not. Then they will say "In the age of calculators, life has become so easy. Too bad that some people are still living in the antiquated times where people were taught how to do REAL MATH!"

Trust me when I say this, the real world situations I have seen in diving were far far more idiotic than the imaginary example I just gave. I would suggest, sitting with your instructor and throwing questions at him for which you are confused. If the man does not make sense then it is not because you are slow to learn. It is because you just have a very bad instructor. I would find someone else.