Question about dive computers

[Stormblessed]

Hello. Just got my ow certification. Looking to buy my first dive computer. Could someone explain what is usually the difference between a beginner dive computer and a mid ranged computer? More specifically, I wanted to know till what point can i use a beginner/budget computer before I need to upgrade. Can I safely use one till the 40m limit? Thanks

 

[almostDIR]

Hello. Just got my ow certification. Looking to buy my first dive computer. Could someone explain what is usually the difference between a beginner dive computer and a mid ranged computer? More specifically, I wanted to know till what point can i use a beginner/budget computer before I need to upgrade. Can I safely use one till the 40m limit? Thanks

mid range computers will usually have some kind of air integration possibility and more options for gas mixes for example. Also they may have the possibility to change gas mixes during the dive.

by my opinion, if you don't need the air integration option, you will probably need a better computer only if you decide to proceed to technical (decompression) diving. the transition probably goes quite naturally if you want to exceed the 40m depth limit because the small depth increases will very quickly eat your bottom time to close to zero if not doing decompression and for nitrogen narcosis control you will want to change to light trimix pretty quickly.
The 40m "limit" for recreational NDL diving is based on mostly practical reasons indeed, you will want to very quickly change to decompression ("tech") diving if wanting to go deeper because it is just not very practical to try to do no-deco dives where you only have couple of minutes of bottom time.

You will want a computer which has basic nitrox capabilities and is easy to use and reliable. the air integration is up to you, I personally don't need it at all but for some it can be useful. You will need mechanical SPG anyway in all cases.
If wanting to do tech at some later point after gaining more experience and training you will know much better which features you need on you dive computer and will purchase a new one anyway. your first computer (if it still works) can then be used as a bottom timer so it does not go to waste.

 

[Rollin]

An entry level Suunto will bring you safely to 40m and will work with nitrox. There are people diving with these computers their whole life. These things can do all a recreative diver wants it to do.

More expensive computers have foremost better and more visible screens (reason why I initially switched), can be air integrated, allow you to use different gasses in one dive including trimix, can have user changeable batteries, use other decompression algoritms, planning the dive is often easier, have bleutooth, have nifty things like @5' (how much decomperssion time will I have in 5 minutes) and so on.

 

[Gareth J]

For the majority of qualified divers world wide. A basic Nitrox capable dive computer is sufficient.

The depth is not the issue. The more advanced dive computers allow you to switch gases during the dive, use special gas mixtures for deep diving, adjust how the computer calculates your decompression requirements, use Closed Circuit (Rebreather) diving equipment, etc. All of this is well beyond what most people will ever use, or understand.

The favourite on this forum is the Shearwater, which is an expensive dive computer for quite advanced diving. An excellent computer, but not required by 95% of those qualified to dive.

Addendum
An additional thought. The cost of upgrading to the newest and baddest, best technical dive computer in the future, when you are doing that type of diving, (if you ever do,) will be insignificant compared with the money you will be spending on the other kit. The $200 you 'write off' on the one you buy now will be insignificant.
Also, give it 2 years, and the best and baddest now will be out of date and not the one to have then!

 

[Damselfish]

I don't think there is any such thing as a "beginner" dive computer. Any dive computer will go beyond 40m. As long as you are sticking to recreational diving, any basic dive computer will do the job. (Just make sure it handles Nitrox even if you don't do that yet, especially if you buy used. Batteries that you can easily change yourself are good, and fairly common now. Make sure you understand it, and ideally like the user interface.) Anything beyond the basics is nice - if you want to buy something with air integration, a big color display, or all sorts of bells and whistles as many folks do, go for it - but don't get fooled that it is required or even necessarily more "advanced."

Should you get into tech diving, you will have another whole set of requirements, but it's not worth worrying about yet. You will spend so much money that possibly buying a different computer will be nothing in the grand scheme of things, and your original can be sold or possibly used as a backup.

I've been diving for 30 years, purely recreational, and still use basic dive computers. Sometimes I get tempted by fancier ones - mostly for those nice displays, I don't need stuff like multiple gases and never will. But if my cheap computer gets lost or floods, it's not so upsetting as if I'd spent >1000 on it, and I'll just pick up another here or on eBay.

I do always dive with a backup computer - as I travel and don't want an expensive and packed week or more of diving interrupted by a failure, that is something important to me. (Some will say just do tables then, but practically speaking that does not work.) For me, 2 cheap computers are better than one expensive one.

 

[JackD342]

To answer your question about safe use within the 40m limit, and not leapfrog you into technical diving, all recreational dive computers are designed to do the same thing - manage your NDL (no decompression limit) and provide you with the information you need to avoid exceeding those limits. The cheapest and the most expensive recreational computers are both performing the same fundamental task.

They may do that in very different ways depending on the algorithm used, and they may present (and store) varying amounts of information to you in varying ways, plus include several other features that may or may not appeal to your personal preferences and your personal budget.

I am including here a general reference document I created a while back, and just recently uploaded to another thread. Look it over, I think it will answer many of your feature/function/cost questions, although I don't get into the different algorithms.

 

[Neilwood]

There are a number of answers to those questions.

Computers tend to be split in to a number of different categories (I am only dealing here with wrist mounted and not console) with the main split being oversized watch type and larger "box" type.

All mainstream computers will happily serve the purposes of anyone doing recreational (within NDL) dives to 40m. Virtually all will handle Nitrox up to 40%.

The main features that differentiate between models of computer are:
1) Screen type - cheaper watch style ones use LCD (with backlights on most) whereas more expensive ones will use LED/OLED. LED/OLED is by far easier to read (I could easily read my buddies LED computer from 5m away whereas I could barely read my LCD without the backlight on.
2) Screen size - size isn't everything but in general the bigger the screen the easier it is to read.
3) Number of buttons: these vary between 1 (where that button does everything depending on how it is pressed or held), 2 (where one button cycles the menu and the other acts as the enter key), 3 (allows for going back and forward through menus) and 4 (allows easier access to certain features). More isn't always better - I prefer the menu structure of my 2 button compared to the 3 button.
4) Additional gasses: basic models will allow only one gas (the one you set at the surface be it air or whatever % of Nitrox). More expensive ones will allow you to add additional gasses which can help get you get of the water quicker by shortening your decompression - this tends to only be an issue when going down the route of technical diving and needs additional training as the additional gasses can kill you if used incorrectly.
5) Algorithm: this is probably the most contentious area. Every computer is made with at least one (some have 2 that can be switched). Some are quite aggressive (will give longish NDL while getting you out of the water fairly quickly) whereas others are more conservative (will give a larger margin of safety). All computers will allow a range of conservatism to allow you to tailor it depending on fitness etc. Read up on the algorithm(s) for the computer you are looking at before you buy it.
6) Battery type: User replaceable, shop replaceable or rechargable are the main choices.
7) Air integration: having the ability to instantly see the state of your gas supply on your wrist is nice but it is doing the same job as an SPG.

I bought a mid level computer (Cressi Giotto) but decided to upgrade it to a more expensive one which was easier to use and easier to see. Nothing wrong with the other but I am happier with the more expensive one I bought.

 

[Rollin]

Well, an entry level Suunto will do quiet a nice job in giving you decompression stops as well. It is not ment solely to keep you withing NDL.
Nice overview by the way. I forgot the digital compass indeed, a feature I use very often.

 

[almostDIR]

I purchased the very basic Zoop Novo during the OW course and will probably use it all to way until advancing to tech diving. I did not like the Mares user interface and the Zoop display is relatively easy to read, that's basically why I chose it and not different model.
You may want to test different computers in LDS to see which is the most logical choice to you. As others said the perfect match does not need to be expensive nor cheap, all of them get the job done and it is more about user interface and display readability when choosing a computer for normal recreational use.

 

[Stormblessed]

Thanks for all the replies!!