Rec Dive Computer for Tech

[DeepBlueDreaming]

I just finished reading Some Introductory “Lessons” About Dissolved Gas Decompression Modeling Presented by Erik C. Baker, P.E. since I posted.

That short paper along with the replies pointing out that the DC doesn't handle He is a very good reason to not use the DC as tech equipment. I believe Dr. Lecter is correct in saying you could easily punch in 3 different nitrox mixes and take a dip with this DC. As centrals pointed out, many tech divers don't use computers. I have learned this from all the reading I've been doing on this site and others. The funny thing is that if I would have waited until after my reading of that paper, I could have answered my own question.

Thank you to those who replied. Thanks Chris, we will have to go diving again soon.

As a side note does anyone have Schreiner, H.R., and Kelley, P.L. "A Pragmatic View of Decompression" in PDF format? I have lots of different papers that I have found online in pdf. Although I haven't read through them all, I do have a question that would shed a little bit of light. How are the half times calucalated for He/N2? Baker presents them in the paper but I didn't see how those numbers came to be. He does explain that Buhlmann gives two different values for compartment 1 and explains why. But how did these numbers find life?

 

[ianr33]

[disclaimer] It also supports 3 different gas mixtures alone with being able to communicate with 3 different tank modules. The DC supports Deco and uses a version of RGBM.

Why would a tech diver use or not use this computer?

Which version of RGBM? Can you play around with profiles on a laptop/ iphone and know how much deco your computer is going to ask for on a particular dive? If not,how do you know how much gas you will need? Knowing how your computer is going to behave in advance of the dive is really useful to say the least.

Let suppose you are doing a sidemount cave dive with a deco bottle of O2. Each tank has a sensor on it.How does the computer react to the pressure in each sidemount tank not changing 50% of the time,and the deco tank being a 1/4 mile away at the cave entrance.

Just get a Shearwater!

 

[tracydr]

While I agree with most of what's written, I see no reason a responsible rec-diver can't enjoy the wonderful features of today's better tech computers, if they so desire. The Liquivision XEO is by far the easiest computer I've ever used, more like an underwater "IPhone". Plus, the screen display is amazing compared to most of what is on the recreational market. Same with the Shearwaters. Great screens, user friendly. They allow recreational diving, are very easy to use and easy to see on night or low-vis dives. If the diver wants to spend the money for them, why not? They aren't any more expensive than an air-integrated something or other.
Is there a fear that the OW diver is going to use that computer to start doing deco dives without training? If so, then why don't you need to show a tech-cert to buy one? And, why beat around the bush. Just tell the OW divers they shouldn't have them because its too tempting to go into deco with them.
If an OW diver has some interest in tech-diving,great,they have a computer that can support it,allows underwater gas changes and a great screen. If they don't want to spend the money, they can purchase one of many less expensive options. But,really, the less expensive options are often hard to see in low-vis and harder to operate. My two older rec-computers drive me crazy when I need to change gas,reset the date-time,etc. Not much better than a cheap digital watch,where I always have to read my manual to change anything. I can't stand that!

 

[Dr. Lecter]

Is there a fear that the OW diver is going to use that computer to start doing deco dives without training? If so, then why don't you need to show a tech-cert to buy one? And, why beat around the bush. Just tell the OW divers they shouldn't have them because its too tempting to go into deco with them.

I doubt that's the issue, and I've never seen anyone even imply that's a reason to avoid tech computers if you're a rec diver. If it was actually an issue, I'd say powerful rec computers like the Cobalt would present a much bigger problem.

Just by way of example, since it's the easiest to use and most powerful (processor-wise) rec computer I know of, the Cobalt's RGBM implementation is designed to plan and execute deeper decompression dives, with the computer even switching over to a more computationally-intensive version of the algorithm for dives planned or conducted below 150'...but it's also much more liberal than anything you'd get from most tech computers. And the exceedingly simple UI makes flying the computer on a deco dive all too easy. Which is fine, until it isn't. does happen, after all... like when your Cobalt floods completely at 190' for no apparent reason towards the end of a 30 minute dive. At that point, you'd better have a backup method of ascending and know how to use it.

The argument as I see it is that tech computers are expensive, and the functionality they offer in exchange for that added cost is largely useless to rec divers. Which is all well and good, except for the fact that lots of rec divers don't want a bare bones computer or BT/tables and if they don't get a tech computer they spend just as much if not more for a POS packed with 'rec features' like the OP's computer or a Galileo or any number of other 'old tech' units that offer a tiny fraction of a Petrel's functionality in a shoddy UI at almost the same price. It also overlooks the fact that, by virtue of what tech divers value, the basic functionality -- things like UI, ability to make changes while diving, screen clarity, data available, etc. -- of tech computers tends to be head and shoulders above the crap peddled to rec divers.

 

[chrpai]

Thank you to those who replied. Thanks Chris, we will have to go diving again soon.

Doh, I'm sorry, I didn't recognize your SB handle and missed who you were. Yes, we'll have to go diving again soon. I didn't really show you any of my gear choices (other then no ditchable weight and donate primary since you needed to know that) or go over my diving philosophy because I don't like to come off as pushy and opinionated to new buddies. But since you are asking questions like this, I can pass on as much as you want if you so care.

 

[robertarak]

Easy:

DG03 Dive Computer and Digital Gauge by Hollis Gear - Dive Gear Express

This will do everything a recreational diver would ever need and a little bit of Tech Lite. If you need more, put it in gauge mode and cut your own tables. If you later decide to get a full helium tech computer you are only out $249 + $19 for bungee mount. And by "out" not really since you'll probably use this as a backup.

Hollis Recalls Digital Dive Computers Due to Drowning Hazard
CPSC - Hollis Recalls Digital Dive Computers Due to Drowning Hazard

 

[DeepBlueDreaming]

Just by way of example, since it's the easiest to use and most powerful (processor-wise) rec computer I know of, the Cobalt's RGBM implementation is designed to plan and execute deeper decompression dives, with the computer even switching over to a more computationally-intensive version of the algorithm for dives planned or conducted below 150'

POS packed with 'rec features' like the OP's computer or a Galileo or any number of other 'old tech' units that offer a tiny fraction of a Petrel's functionality in a shoddy UI at almost the same price. It also overlooks the fact that, by virtue of what tech divers value, the basic functionality -- things like UI, ability to make changes while diving, screen clarity, data available, etc. -- of tech computers tends to be head and shoulders above the crap peddled to rec divers.

The Cobalt and Icon both use a rec version of Wienke 10 tissues RGBM. As far as microprocessor power, I was unable to find those specs. In regards to UI, the Icon, IMO, far exceeds the Cobalt and so does the ease of use. I researched both before I purchased a DC. I was leaning towards the Cobalt until I got my hands on the Icon. Both have their own draw backs and bugs and they are somewhat close in price. But at the end of the day, the Icon provides all information in a clear and straightforward approach.

Alright, I think we have clearly discussed the use, or lack there of, of the Icon dc in tech diving. My question was answered.

Thanks.

Still looking for that pdf though.

 

[chrpai]

Hollis Recalls Digital Dive Computers Due to Drowning Hazard
CPSC - Hollis Recalls Digital Dive Computers Due to Drowning Hazard

Considering this a Rec for Tec thread..... who here would actually use AI? Not me hence that recall isn't relevant. I don't consider AI a "need" or a "good thing". #gasplanning

 

[robertarak]

Considering this a Rec for Tec thread..... who here would actually use AI? Not me hence that recall isn't relevant. I don't consider AI a "need" or a "good thing". #gasplanning

Considering this is a public forum, who here would consider recommending a computer with a recall and a known defect that could cause death?
I thought maybe you were unaware, and I was just supplying information. It is sad to think that you knew of this issue and chose to post this recommendation in a public forum anyway.

 

[chrpai]

Products get recalled all the time. There's a firmware upgrade that's available that resolves the issue.
If you buy a Hollis DG03 from DGE it's already going to have the firmware upgrade. I didn't see anything worth mentioning.

Why are you making such a big deal out of nothing? Could it be because you are a Liquivision dealer? Should I suddenly make a big deal about an explosion hazard recall they had?

FWIW, I've actually dove with the OP and I have no desire for him to either die or spend too much money on something he doesn't need.