Can dive computers alter the laws of physics?

[Heffey]

I must be a little bit thick because I just don’t get it. I read a lot of posts about dive computers and there is a recurring theme that leaves me completely dumbfounded.

People keep writing about wanting a computer that is not too conservative or not liking what their computer is telling them on their dives. I’ve read about people being mad that their computer locked up and others write about it being frustrated because their computer doesn’t have an override feature which allows them to get more dive time.

I guess I don’t follow the “too conservative” thing. Is the dive computer safety equipment or just a subjective reference tool?

When I buy my dive computer I will buy the one which I feel will keep me the safest. I know that will still run the tables for the dive as a base model and I will never blindly trust the computers data. When it comes to my safety I am conservative.

How do you dive your computer and why?

 

[teknitroxdiver]

As you probably know, a computer constantly calculates NDLs based on what depths you've been to and for how long. Then on top of that they add a safety factor. Some add a lot, some not as much. Those that add a lot irk some people who didn't know that before they bought the computer, because they don't want a 10-minute safety margin.

 

[Blackwood]

Just like the tables, a computer is estimating nitrogen levels.

There is such a thing as being conservative to the point of ridiculousness. An example of that is treating a multi-level dive as a single level dive at the greatest depth. Unless you are planning your dive and diving your plan, I fail to see how one can check the computer with the tables. I also fail to see why it's reasonable to blindly trust empirical tables but NOT a computer that does realtime calculations based off similar (and often the same) data.

 

[jhelmuth]

I must be a little bit thick because I just don’t get it. I read a lot of posts about dive computers and there is a recurring theme that leaves me completely dumbfounded.

People keep writing about wanting a computer that is not too conservative or not liking what their computer is telling them on their dives. I’ve read about people being mad that their computer locked up and others write about it being frustrated because their computer doesn’t have an override feature which allows them to get more dive time.

I guess I don’t follow the “too conservative” thing. Is the dive computer safety equipment or just a subjective reference tool?

When I buy my dive computer I will buy the one which I feel will keep me the safest. I know that will still run the tables for the dive as a base model and I will never blindly trust the computers data. When it comes to my safety I am conservative.

How do you dive your computer and why?

Why do you need one if you will never blindly trust it (I assume you mean that you will plan your dive and dive your plan) - yet you will buy the one which will keep you the safest (isn't that you?). If you are conservative, then how does the computer keep you the safest (since you are the one in control of your diving - not the computer)?

Actually... I'm the thick one here - I don't get it.

 

[rje634]

There have been times, at the end of a long dive week, where I've hovered 15 to 20 feet above the dive group because I'm saturated and the computer is saying I'm running out of NDL time. So I reduce my depth to increase my NDL and stay with the group.
I dive with a Suunto and I know there known for being conservative, but I'd rather be conservative and be able to dive the next day instead of possibly spending the day in a chamber.

 

[rje634]

Just like the tables, a computer is estimating nitrogen levels.
.....
I fail to see how one can check the computer with the tables.

I usually check my dives with the tables (just to see what pressure group I'm in), I've have almost never been within the NDL limits of the table. This is one of the benefits of using a computer, getting credit for the shallower portions of multi-level dives.

 

[Canadian_Diver]

How do you dive your computer and why?

I completely agree with everything you said.

The computer is another tool for safety. I keep my dive tables in my dive bag at all times, however, they don't come out unless I'm doing alot of repetitive dives, or my computer fails.

Other than that, I obey what my computer tells me, I never dive a reverse profile, and I always keep in mind my physical / mental abilities and limitations.... and I always add on extra time for my safety stop by burning my tank down to 500psi, even if I still have 1000psi left after my safety stop.

 

[Blackwood]

I usually check my dives with the tables (just to see what pressure group I'm in), I've have almost never been within the NDL limits of the table. This is one of the benefits of using a computer, getting credit for the shallower portions of multi-level dives.

Do you do it with standard "table methodology" (i.e. deepest depth reached for total bottom time)? Or do you spend the time to assume a 0 surface interval between each depth at which you stop?

 

[rje634]

Do you do it with standard "table methodology" (i.e. deepest depth reached for total bottom time)? Or do you spend the time to assume a 0 surface interval between each depth at which you stop?

I do standard table methodology. That why I'm off the charts most of the time.
Too hard to keep track every depth I spend time at.
Maybe I should learn how to use the wheel..... Nah...

 

[Blackwood]

I do standard table methodology. That why I'm off the charts most of the time.
Too hard to keep track every depth I spend time at.
Maybe I should learn how to use the wheel..... Nah...

Nah is right. I actually find that it's faster to use the tables as I laid out above than it is to use The Wheel (though I'm obviously lacking the Multi Level dataset). Waste of 50 bucks if you ask me...