"conservative" vs "liberal" computers

[manni-yunk]

In reading a lot of information on computers, and researching what one to get next summer, I have seen a lot of you guys talking about certain computers being
"fairly liberal" or "slightly conservative". The manufacturers obviously dont describe them that way and stop short after letting you know that they have a "deep stop" programmed in that is recommended.

That being said - which computers tend to be more conservative than others. At this early stage of my diving, I would rather have one that is conservative. I am not as concerned about how easy to learn it is. I sell hardware and software that is extremely complex and I can read and understand technically written directions extremely well.

I also dont want one that is overly basic (non-nitrox above 21% capable) etc.

What are some of the basic differences- number of buttons, difficulty in changing modes, ability to change battery,makeup of screen material, downloadability, etc, that I should be looking for and what are their relatve importance?

 

[Gerbs]

Best bet would be to ask in the computer and gauges forum...

Having said that... It's a lot of personal preference. Having seen an X1 in the flesh, I am not ever buying a computer without an OLED screen....

Without going into a 35 page essay on the philosophy of dive computer design which would be the most extreme interpretation of your rather broad question, I would suggest to keep in mind the following:

1. Where to mount? Wrist or console?
Personal preference: Either a good wrist strap long enough to deal with thick suits or a bungee mount, as I can move my arm quickly to look at what I need without digging for my console. Also means I don't need to move far which means I don't need to flail around upsetting my trim.

2. Illumination
OLED is amazing but expensive, active ilumination either drains batteries quickly or turns off when you least need it. Phosphorescant sucks, as you need to keep charging the display with your torch at night. I have a phosphorescent computer, next one is going to have an OLED display.

3. Batteries
The first time your computer fails from an exhausted battery first day into a week long diving trip, you will be glad you got one with user replaceable batteries.

4. Gauge Mode /Multi Gas / PC interface
If you go to do more advanced stuff nearer tec than rec, you will want to have a computer that can handle you switching from air or low-octane nitrox to a higher mix or pure O2. (40m, 30min: deco 59 minutes if all on air, use nx28 and a 100 mix for deco, and total deco is 16 minutes). Failing that, if you go tech, you will end up using run-time tables anyway, so a depth/time mode without calculating decompression is useful. Here, the PC interface for downloading starts to be useful rather than a nice toy.

5. Air integration
A good, expensive way to ruin a dive is if someone helps you with putting on your equipment and picks up your rig by the wireless pressure transmitter.

If you are not wanting to go into tec just yet, then a Suunto Gekko or Vyper will get you far. They are conservative, and the Vyper will give you gauge mode for anything advanced you want to do.

The Vyper is the computer I normally recommend when asked, as it is self-illuminating, conservative, has enough modes for most people, can download to PC, the battery is user changeable and it is relatively cheap. If money is no object, get an Heinrichs Weikamp OSTC or DR5, Liquivision X1 or Shearwater Predator, never needing to wonder if you bought enough computer...

Gerbs

ps: Mods: feel free to move my reply to the right subforum.

 

[ianr33]

If you are not wanting to go into tec just yet, .

The OP has less than 25 dives. I doubt he is ready to "get into tec" "just yet"

My $0.02 Get a simple,wristmount Aeris/Oceanic type computer that is nitrox capable.These are pretty aggressive but guess what? You dont have to dive them that way!!!!! These computers have a nitrogen loading graph that goes green,yellow (caution) and red (deco) Very simple,very intuitive. Dive to the edge of the red and they are aggressive. Always keep it in the green and its pretty conservative.

I see no reason to have a conservative computer. Neither do I see a reason to have air integration,digital compasses,heart rate monitors etc etc etc.

 

[manni-yunk]

Best bet would be to ask in the computer and gauges forum...

Having said that... It's a lot of personal preference. Having seen an X1 in the flesh, I am not ever buying a computer without an OLED screen....

Without going into a 35 page essay on the philosophy of dive computer design which would be the most extreme interpretation of your rather broad question, I would suggest to keep in mind the following:

1. Where to mount? Wrist or console?
Personal preference: Either a good wrist strap long enough to deal with thick suits or a bungee mount, as I can move my arm quickly to look at what I need without digging for my console. Also means I don't need to move far which means I don't need to flail around upsetting my trim.

2. Illumination
OLED is amazing but expensive, active ilumination either drains batteries quickly or turns off when you least need it. Phosphorescant sucks, as you need to keep charging the display with your torch at night. I have a phosphorescent computer, next one is going to have an OLED display.

3. Batteries
The first time your computer fails from an exhausted battery first day into a week long diving trip, you will be glad you got one with user replaceable batteries.

4. Gauge Mode /Multi Gas / PC interface
If you go to do more advanced stuff nearer tec than rec, you will want to have a computer that can handle you switching from air or low-octane nitrox to a higher mix or pure O2. (40m, 30min: deco 59 minutes if all on air, use nx28 and a 100 mix for deco, and total deco is 16 minutes). Failing that, if you go tech, you will end up using run-time tables anyway, so a depth/time mode without calculating decompression is useful. Here, the PC interface for downloading starts to be useful rather than a nice toy.

5. Air integration
A good, expensive way to ruin a dive is if someone helps you with putting on your equipment and picks up your rig by the wireless pressure transmitter.

If you are not wanting to go into tec just yet, then a Suunto Gekko or Vyper will get you far. They are conservative, and the Vyper will give you gauge mode for anything advanced you want to do.

The Vyper is the computer I normally recommend when asked, as it is self-illuminating, conservative, has enough modes for most people, can download to PC, the battery is user changeable and it is relatively cheap. If money is no object, get an Heinrichs Weikamp OSTC or DR5, Liquivision X1 or Shearwater Predator, never needing to wonder if you bought enough computer...

Gerbs

ps: Mods: feel free to move my reply to the right subforum.

Thank You for the reply - I will look into the Gekko and Vyper.

And for the record. I didnt even realize that there was a computer and gauge forum??
Sorry. I have spent a lot of time reading scubaboard over the last month, and have done tons of searches- I just never scrolled down that far on the page....Sorry.

 

[manni-yunk]

The OP has less than 25 dives. I doubt he is ready to "get into tec" "just yet"

My $0.02 Get a simple,wristmount Aeris/Oceanic type computer that is nitrox capable.These are pretty aggressive but guess what? You dont have to dive them that way!!!!! These computers have a nirogen loading graph that graph that goes green,yellow (caution) and red (deco) Very simple,very intuitive. Dive to the edge of the red and they are aggressive. Always keep it in the green and its pretty conservative.

I see no reason to have a conservative computer. Neither do I see a reason to have air integration,digital compasses,heart rate monitors etc etc etc.

NO tec, not yet. But I wouldnt be surprised if that was where I ended up someday- after many, many,many more dives and much more training.

I agree about the wrist mount and agreed that I do not want air interation, etc. But, on the conservative point- well,at this point I disagree about about not seeing a need for it. But then again, I'm new to this, maybe I will change my mind or learn something. For now, I would prefer to stay on the conservative side of things.

 

[Gerbs]

The OP has less than 25 dives. I doubt he is ready to "get into tec" "just yet"

Yeah, I know. It's just that mostly there are two divers who are just starting... "Oh, Look, Pretty!" and "Wow, cool, want more!". There is a subtle difference between them. While the former is off to tropical waters and guided reef tours in shallow water to look at funky fish, the latter is likely to dive a lot, followed by quickly progressing certification, hopefully matched by experience gained equally quickly.

In case of the latter, thinking one step ahead of current requirements makes sense. If I buy a new car, I'll get one with a towing hitch, not because I want to do towing, but because it gives me options which I might want to exercise at some point.

As for diving an aggressive computer conservatively, that is a good point. However, the way human nature works is that we want to go further. (If we didn't want to go further than land, we wouldn't have started diving!), and there is the temptation to get closer and closer to the limits. In the case of progressive dive computers and multi-day dive trips with loads of diving, the margins get thinner and thinner.

For technical diving, an aggressive computer might make sense as an option 2 to your conservative computer, to give you a faster, controlled way of ending the dive quicker. However, for this kind of diving, what kind of computer doesn't matter, as chances are you end up cutting your own tables or know how you can get away with bending your computer (The fast compartments are the ones you don't want to hurt, so cut the shallow stops to trade bends for surfacing if you do need to risk it, reducing the risk of the nastier neurological hits).

Let's face it, time spent underwater is in all cases better than time in a chamber, and I already paid for the air... So what's an extra 15 minutes* of deco for peace of mind? (assuming gas planning has been taken into account)

*= Actual example - Suunto Gekko on +1 conservative (middle value) vs a Uwatec Aladdin on the same dive profile.

Gerbs

 

[Blackwood]

Let's face it, time spent underwater is in all cases better than time in a chamber

It's pretty hard to drown in a chamber.

 

[deich]

Take a Look at the Dive Rite Nitek Duo

It is not as "conservative" as the Gekko, but is able to add layers of conservity... (is that a word)

Anyway it is a great conputer at a great price i have been diving the Tusa version for years...

NiTek Duo Dive Computer by Dive Rite - Dive Gear Express

 

[DA Aquamaster]

I would recommend getting a wrist mounted two or three gas computer like the Uwatec Tec 2G, Nitek Duo/Tusa IQ-700 or the Nitek Trio.

As stated above the OP is not interested in tech quite yet but, for example, the Tec 2 G offers a lot to a diver just starting out, plus growth potential that will prevent buying 2 or 3 computers in a short period of time.

1. Download capability with inexpensive / free software that will work with a $20 IR interface.

2. Superb bungee mount options from Deep Sea Supply ($8).

3. Nitrox capability up to 40% for the first gas

4. Five levels of user adjustable conservatism that will allow it to meet just about any desired level of conservatism and/or be compatible with a buddy's other brand computer.

5. If the OP goes the tech route, the Tec 2 G will handle a deco gas up to 100% O2 and can be used in guage mode as a bottom timer at the trimix level, and

6. It does not cost much more than a run of the mill nitrox computer that has much less growth potential.

The computer also has a graphic nitrogen loading bar that allows the user to monitor the currently critcal gas compartment in the model and further adjust the conservatism by surfacing before the N2 gets into the yellow,m or extending the safery stop until it is back in the green.

Pretty much the same arguments apply to the other two computers mentioned above.

 

[Jax]

My vote is for the Uwatec TEC2G . . .

I'm a novice, too.