Dive Tables VS Dive Computer

[Rosevb]

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?

*Edit* Our course did teach us how to use the table and eRDPml, and we had to answer questions about it on our exam. However we dove walls in fairly deep water with constantly changing depths, so we were never actually asked to use the tables for a real dive. This is why I am confused now that I am wanting to start diving without a dive master.

 

[KenGordon]

People like to spout on about about how the medieval methods they learned are better.

The truth is a dive computer is what you want. Tables are useful for planning to an extent but practically are hard to use. Tables are also based on assumptions which may not be true for your diving and restrict bottom time pointlessly.

Some people will claim that teaching tables somehow helps students understand deco theory. Or we could just teach deco theory.

 

[Graeme Fraser]

To use stand alone tables you need a timer AND a depth gauge. Realistically, with reliable, inexpensive, entry level dive computers on the market, there is no point spending nearly the same amount on a gauge.

Depending on your budget, dive computers range anywhere from $150 to $1500.

 

[Griffo]

Dive table planning during OW training does in my mind provide a basic minimum understanding of Deco, and re-enforce to people that the deeper you dive, the shorter your NDL.

In real life though, pretty much most recreational divers simply "fly their computer" whereby they follow the NDL the computer is telling them during the dive. They may use the planner function on deeper or repetitive dives, but even that seems rare in the recreational population.

If you're asking whether you should get a basic bottom timer vs computer, there's zero option imho. Get the computer.

 

[JohnnyC]

Tables are a great teaching tool because they show a "big picture" view of the relationship between depth and time, ongassing and offgassing. This allows students to see an overall understanding of how each effects your inert gas loading, and in turn the physiological implications.

Practically speaking however, they are inferior to a dive computer in many ways. There's a reason that most agencies are moving or have already moved to a computer-only OW course.

 

[loosenit2]

You are absolutely correct that most watches marketed for diving are as expensive as an entry level dive computer, but there are many options that are much less expensive. In general if you are diving at recreational depths, than a watch rated to 200m should be just fine. The 34 dollar Casio below is a good example of an inexpensive watch that can act as a bottom timer and it specifically says good for scuba diving in recreational depths. You just have to ensure that you have a depth gauge in your console (common to almost all rental gear)

https://www.amazon.com/Casio-WV200D...apparel&sprefix=200+m+wat,fashion,154&sr=1-26

Others are right to point out the advantages of computers though, you really do get a lot more bottom time from the continuous depth monitoring of a dive vs calculating nitrogen loading using tables where you assume your deepest depth was your depth the whole time (a square profile).

Another option is to rent a computer along with your other dive gear which many will recommend until you get a feel for what you want in a computer.

 

[Jcp2]

Try before you buy. Once you get access to a dive computer, go into its planning mode and play around with it. If you do this while reading your open water manual, you can get a better sense of what depth does to nitrogen levels and no stop time.

 

[Marie13]

Just get a computer. If you intend on just diving on vacation, one of the basic AquaLung, Oceanic, or Suunto computers are affordable and will
work well enough.

There’s no reason to use outdated methods (tables) when there are better options out there.

 

[Neilwood]

Just get a computer. If you intend on just diving on vacation, one of the basic AquaLung, Oceanic, or Suunto computers are affordable and will
work well enough.

There’s no reason to use outdated methods (tables) when there are better options out there.

Agreed - tables might be ok as an aid for teaching to reinforce the relationship between depth, time and NDL but in real world diving, their effectiveness is limited. They are very effective if you are doing square profile dives (straight down, stay at a fixed depth, and straight back up) but as soon as you start changing depths during a dive they lose their effectiveness quickly.

 

[arcticat99]

holy crap not one comment about shearwater yet im impressed .oops kinda blew it lmao