Dive Computer Question

[cwhite6]

I am surfing the internet and reading all I can while waiting for my cert class in July. I have been looking at different dive computers. While not planning on buying one right away, I have some questions.
1. I am assuming air integrated means the computer is connected by a hose or wireless to a module on a tank to your air supply. Is this right?
2. How does a non air integrated computer figure out dive time left if it does not know the air left in the tank or your usage at the moment? Does it only show you time left to avoid deco stops?
3. Is air integrated something I should try to get? They are pretty expensive. My hope is to learn and do nitrox, wreck, and night and deep diving, but not technical diving. I would like to avoid rebuying stuff. As in I will be buying a cold water nitrox able regulator when I buy one. Don't need it know, but I may later.
4. I am guessing your normal dive computer setup is with a pressure gauge below it and a compass above it? Is this right?

Sorry for some of the basic stuff, but the only dive shop local to me is only open 3 times a week and they have a very small selection of stuff. It would be real nice to have a large one here where I could just walk around and look at stuff.

 

[Bubbletrubble]

1. I am assuming air integrated means the computer is connected by a hose or wireless to a module on a tank to your air supply. Is this right?

Yes.

2. How does a non air integrated computer figure out dive time left if it does not know the air left in the tank or your usage at the moment? Does it only show you time left to avoid deco stops?

A non-air-integrated computer does not track your gas supply at all. For the most part, it only tracks dive time, current depth, temperature (sometimes), and displays the No Deco Limits at the current depth. Nitrox-capable computers in nitrox mode also keep track of oxygen exposure units.
It's up to the diver to keep track of his gas supply separately. During a dive, whenever a diver checks his remaining gas pressure, he should always be asking himself: "Do I have enough gas to complete the dive as planned?" "Do I have enough gas to get my buddy and me to the surface safely (in case my buddy is low-on-air or out-of-air)?"

3. Is air integrated something I should try to get? They are pretty expensive. My hope is to learn and do nitrox, wreck, and night and deep diving, but not technical diving. I would like to avoid rebuying stuff. As in I will be buying a cold water nitrox able regulator when I buy one. Don't need it know, but I may later.

None of my computers are air-integrated. For various reasons, I prefer to track my gas supply independently. You'll have to decide whether you want to pay extra for the air-integrated feature.

4. I am guessing your normal dive computer setup is with a pressure gauge below it and a compass above it? Is this right?

I don't know if there is a "normal" setup anymore. The way I have my reg set up, I have an analog SPG attached to a HP hose on the 1st stage. I wear my compass in a wrist-boot with bungee straps on my left wrist. I wear my non-air-integrated dive computer on my right wrist.

 

[raftingtigger]

cwhite6,

I'll try to help you out, but I'm no dive computer expert

1. Yes
2. A non-air integrated computer is only giving you NDL (No Deco Limits) left. Gas management isn't calculated
3. Up to you. My thoughts are what is more likely to fail underwater? A mechanical pressure gauge or an electronic device? Do I want to be without pressure info?
3a. Nitrox able regulator? Standard Nitrox is less than 40% Oxygen, therefore ALL regulators are Nitrox capable. This is probably different for a dedicated deco stop bottle/regulator with >40% O2...
4. It's up to you. I don't like having my computer and spg on opposite sides. I like being able to glance at both of them at once. I also clip my console across my chest so I can see it all without touching it. I've got my compass on a retractor. It's easy to handle and stays out of the way.

Finally, the only stupid questions are the ones you don't ask.

 

[cwhite6]

Thanks for the info!!!

 

[cwhite6]

Nitrox able regulator? Standard Nitrox is less than 40% Oxygen, therefore ALL regulators are Nitrox capable. This is probably different for a dedicated deco stop bottle/regulator with >40% O2...

I asked that question because I have read on this board and others in advice to people buying regulators to get one that is able to be used with nitrox. I have no idea if there is such a thing. Is there? If I am planning on only recreational diving with under 40% oxygen, then any regulator is capable of that?

 

[Bubbletrubble]

I asked that question because I have read on this board and others in advice to people buying regulators to get one that is able to be used with nitrox. I have no idea if there is such a thing. Is there? If I am planning on only recreational diving with under 40% oxygen, then any regulator is capable of that?

Just so I'm clear on this...
The thread title is "Dive Computer Question," yet you are now asking a question about nitrox-compatibility of regulators, correct?

As raftingtigger pointed out, the vast majority of modern-day regs may be used with nitrox mixes up to 40%. When you're researching regs to buy, just make sure that that's something you verify on the manufacturer's website.

It's generally a good idea to purchase a dive computer that's nitrox-capable. That feature doesn't cost much nowadays. Most nitrox-capable computer can be used with nitrox mixes in the 21%-50% range.

 

[Druid]

I asked that question because I have read on this board and others in advice to people buying regulators to get one that is able to be used with nitrox. I have no idea if there is such a thing. Is there? If I am planning on only recreational diving with under 40% oxygen, then any regulator is capable of that?

Pretty much any regulator will be fine for use with nitrox mixes up to 40%. I have an air integrated computer, it's good to have all the info I need in one place - a glance at my wrist tells me everything I need to know, but I still have an analogue SPG as well (belt and braces )

I wear my computer on my right arm, SPG clipped of to my left hip and my compass in my drysuit pocket - they're not much use on wrecks.

Edit: Bubbletrubble, I'm having a hard time thinking of a new dive computer that isn't nitrox capable.

 

[cwhite6]

Thanks for the clarification. I may have confused computers and regulators in people's posts.

 

[Seraphimx]

I also had those questions not long ago, don't worry.

For your pockets I'd say stay with a basic computer.

I bought a wireless computer as soon as I could and I ended up selling it and buying a basic computer.

Furthermore, I find that console or console computers are bulky and annoying, a computer can easily fail if the batteries are dead, while an Analog pressure gauge doesn't really need much maintenance except the yearly check up.

What I have now is like BubbleTrubble has:

- A SPG attached on the left side, a hose just the right length so it doesn't bother you,.

- A wrist mounted compass on my left arm

- A wrist mounted computer on the right arm
Most computer nowaday are nitrox compatible. I'd recommend buying the cheapest one now and buying another later on. I bought the expensive one at first think of the "long term" usage. But seriously, I haven't used 1/2 the features and the computer cost 700$, while my 250$ one does MORE than what I need it for.

Scuba is an expensive sport, don't fall for the shinny toys just yet.
Thinking back about what I bought, a Computer would be on my top list of what new divers should buy.
Renting a computer is tricky, you can rent the rest of the gear and still keep your dive watch/computer.

Also, if you wish to connect the computer to your PC look at the connection cable and setup. Some companies sell the computer cheap and then ask a whooping 200$ for a PC connector to log your dives unto your PC.
Sometimes its cheaper to buy a more expensive computer "50$" not to spend "100$" more on the cable.

 

[gNats]

I have a Suunto Cobra, air integrated Nitrox (and air) computer. The hosed computer is sold either with or without a compass attached to the housing. PS: You can add the compass to the housing at a later date if $$$ is a factor.

If you have an air integrated computer, you do not need an spg. The computer acts as your SPG. And, although it will tell you time remaining (based on air volume) what you are really watching is the no-deco limits and nitrogen buildup. Why? Because, assuming you are not an air hog, you will probably hit the NDL maximum long before remaining air TIME is an issue.

Hose versus Wireless. Each has drawbacks. A hose can get tangled. A hose is only so long and if you need to stretch it out further (for visibility) or move it closer you may not have the flexibility. Wireless has similar cons however. I have heard of people who lost "transmission" during a dive because the computer was in an odd angle away from the transmitter. transmitters fail. Transmitters (CAN) sync to another similar dive computer (That I have seen happen).

I preferred the hosed version myself.

Another issue with computers is conservatism. Some computer manufacturers, such as Suunto, have very conservative algorythms. When I first bought my Suuno I thought "YES! More safety!" But after a hundred dives where I could make a steel 80 last for over 50 minutes at 75 feet, I was very disappointed when my computer starting screaming at me and my buddy was still in the "green" zone.

Another thing to consider is readability. If you can visually inspect several computers, do so. Put on a mask. Fog it slightly. dip your head in a pool with a towel over it. Can you READ the display? My Suunto has nice big numbers and the back light does help readability in a murky lake. But, this is a subjective feature. Some people can read the smaller print, some cannot.

If you can't read the display at 40 feet in murky water, um. Air integrated is a moot point, right? :-D

Does the features make intuitive sense to you? If you have to push 2 buttons to set a feature or go through a menu to see the temp, does it come easy or not? Some people find some computers easier to use than others. Very personal and subjective. But, the key is what is best for you. Because at 60 some feet, you will need to flip through the screens to see the information. Not the other posters on this forum.

If you get a HOSED computer, get the quick disconnect. This is a connection on the hose that allows you to remove the computer from your regulators EASILY. Without taking the hose off the first stage. Most computers download to PC/Mac, so you can synch without dragging your regs through the house. Also, I like to keep my computers stored differently than my regs. So this allows you more "safety" in handling.

If I had to shop for my first computer all over, I would choose readability and instictiveness to use first and then the algorythm. If that computer came hosed versus wireless (not all do) then I would make that choice.

Oh, sorry, 1 more thing. I no longer dive air integrated, I am stepping into tech and multi-gases. However, when I do dive single gas recreational diving, I continue to use the air integrated computer. why? Because it is 1-stop shopping. One gadget. All the details. I don't have to check the SPG and then look at the computer.

If you are a single gas, recreational diver, then air integrated is a great computer. Once you get into multi-gases (while following tec training route), then you need an SPG and non AI Computer. And, yes, they can fail. All SCUBA diving equipment can fail. My Suunto has over 100 dives on it and the battery is still showing "full." I think more people will speak (from DIRECT EXPERIENCE) in favor of air integrated than share failure stories (where user error was not the direct cause of the failure.)

Hope this helps.