Decompression Thoughts

[jimbo]

Having done only a few dives, I am wondering about the merits of buying a decompression capable computer vs the cheaper (sorry - less expensive) models that don't handle decompression times. Any thoughts? Any any computers better suited to cold water diving?

 

[TexasMike]

IMO, I would rather have a computer that would handle stops for the instance where I get so wrapped up in the diving that I do violate my NDL's. Plus I plan on eventually doing deeper dives on both air and nitrox (as in below 100 fsw), so having this capability is important.

Since we don't dive a square profile like the tables "compute" (we go down, we go up, we go down again, we go up, repeat ad nauseum), computers are a big help in ensuring that we get the maximum time our air consumption will allow and not get bent. So I feel it's in our best interest to have all the features/capabilities possible to ensure our safety, including providing for deco stops if necessary.

Most of the computers sold these days DO handle deco stops in one form or another. And I'm not aware of any current models that don't.

Chosing your computer is not unlike making other gear choices like your reg and BC. You need to take into consideration what type of diving you will be doing this season and 5 to 7 yars down the road. This way you can look at your purchase as an investment for future excursions rather than having to replace it beause you grow beyond it's capabilities.

My Genesis ReAct computer works very well for me and it will compute deco stops if required. The only reason I would change is because I want a feature that it doesn't provide (such as air integration).

Mario check me on this....colder water decreases your NDL's right? Are there any computers that take this into account when doing their calculations?

 

[jmsdiver]

Of course, the question begs another question: what type of diving are you doing? If you are leaning toward decompression type diving, then analogue gauges and decompression schedule on a slate are the way to go, though the Abyss line of computers is looking promising from the reviews I've seen thus far (expensive line of computers, any other thoughts here?). However, if you are like me at this point, I prefer a computer that can give the data that is needed to get back "home" versus one that is going to lock up in violation mode. Most computers out there today offer some kind of decompression mode, you'll be hard pressed to find one without. But, some are more forgiving than others after you get back to the surface: many lock up until their model says it's ok to dive again, others continue to calculate dives. Keep that in mind when purchasing a new one.

Cheers and safe diving

 

[Warhammer]

The fact that most of today's computers will provide deco information doesn't mean that they are suited for deco diving. In fact, most of the manufactors strongly advise against using them as such. To my knowledge there are only a few that are suited for it, the Dive Rite Nitek 3 for instance. Most of the others show the info for contingency purposes only. Meaning that if you inadvertantly go into deco, you have a way out. If you want to do deco diving, then seek professional instruction on the princibles and procedures of it. Just my $.02. And a good place to learn would be Bikini Atoll and I be willing to chaperone anyone willing to pay my way.

 

[Lost Yooper]

If I were going to be a recreational diver, I'd buy the cheapest computer out there that can get you out of trouble like an Aladin Sport. Here's why. It will do everything you 'll need it to do and will probably get you out of the water if you screw up. Why the cheapest? Because as a recreational diver, you won't need all the extras. I would forget about the air intergrated things out there since a failure would really suck, and they are too expensive.
If you end up going on to tech stuff and read the learn the right stuff, you find out that a good bottom timer and deco program is the best way to go. Why? Most deco computers are more conservative than is necassary, it would really, really suck if it failed, and are too darned expensive.

That's one point of view.

Mike

 

[scubabunny]

One problem with the Aladin Sport is it doesn't do Nitrox. If you are going to go into Nitrox, I would go with either the Aladin Pro Nitrox, or the new Aladin Pro Ultra. But, the Ultra doesn't fit into a console..yet. The Pro Nitrox and Ultra are both able to do Nitrox, plus they don't get
"freaked out" by Deco dives. In fact, you can try to pre-plan deco dives by simulating them.

Drawback...have to send them back to the company to get the battery changed. But...they do last for a loooong time (as long as you don't let them soak for weeks on end like I do!)

Another option is the Data Plus 2. A very basic and reasonable priced computer. Fits into alot of consoles, or hose mounts or wrist mounts are very affordable. It is not made for deco, but will talk you through it.

As said before, it depends on where you are heading...but if you DON'T know at this point, I would suggest one of the above. If you are planning to go into extended range and all that..these will still make great backup computers.

 

[omar]

The Aladins do get freaked out by deco dives. I have worn mine on a couple of deep dives and bent the crap out of it. I wanted to see what would happen to it on a 185 foot dive. I was out of the water and feeling fine and my pro nitrox was beeping like crazy for 5 minutes until it locked up for 36 hours. The second time I left it in the water at 10 feet on a line for 25 minutes until it cleared.

A bottom timer and tables are all that I use and need for deco dives. The Aladins are not good for deco dives unless you want to spend an ungodly amount of time decompressing. In addition they do not handle multiple gases. Any air computer can be used for nitrox. You just will not get the benefit of extended NDL times. For most recreational divers this is not an issue anyway.

omar

 

[jimbo]

ok, I should clarify.....I'm still looking at low cost computers since I'd like to maximize my time in the water without maximizing my Visa bill. I haven't got enought experience to know what I'm going to want in 5 years so maybe I should go low-cost and be prepared to upgrade to a nitrox/air cadillac model when the time is right. Is my reasoning hooped?

 

[turnerjd]

Originally posted by jimbo
ok, I should clarify.....I'm still looking at low cost computers since I'd like to maximize my time in the water without maximizing my Visa bill. I haven't got enought experience to know what I'm going to want in 5 years so maybe I should go low-cost and be prepared to upgrade to a nitrox/air cadillac model when the time is right. Is my reasoning hooped?

Jimbo,

Your reasoning is far from hooped! Buying a computer that is the dogs bollock* to begin with is 1) painfull on the wallet after you have just bought all the other bits, 2) not going to give you much advantage untill you have done plenty of dives, and have you air consumption right down, and 3) will inevitably be wrong, or just plane not what you want in 5 years time, so you will spend the same again on a replacement.

So, starting with the cheepest,

PADI Wheel - probably the most laughed at product out there, but, for £35 (when I bought one) you get the ability to do multi level, and get quite some extra time underwater. If you are still in the low dive numbers, you will probably get quite some use from it as your air will still run out before your multilevel NDL approaches. However, you have to have some discipline to dive with it (plan the dive and dive the plan). If you have the discipline - dive on this untill you have a)got experience to know what you want from a computer, and b) saved up the money for a propper computer.

Cheap computer - good if you have poor discipline / planning, or just plane don't fancy the wheel. If you chose carefully now you can get one with the same basic algorithm later, and the cheep one can act as your backup, although without some of the functionality of the 'propper' computer. the cheepest I have seen is the Suunto Octopus II for £91 on Diveinn.com ...... You can't go too far wrong!


Jon T

 

[scubabunny]

Ok Omar, I apologize. You are right..Aladins DO freak out if you are purposely doing deco dives and NOT paying attention to the computer. But, I figured Jimbo was not a "tec" diver or doing Trimix, and was looking for a safe computer to talk him through deco stops should he happen to find himself in that situation.

Bottom line Jimbo, using a computer is the best way to go (sorry guys). I think most people on the board will agree with me. It will maximize your bottom time, is much safer than depending on the tables, and allows you to enjoy the reason you are down there to begin with..to see what you can see!

I still stand by the Aladin or Data Plus 2. My Aladin has never failed me. And both do Nitrox. They are great for recreational diving.