How penalizing are cheaper computers at "deeper" dives

[RyanT]

If you don't know how much hang time your computer is going to give you, how do you know if you'll have enough air? Also, what if someone else has a gas emergency? Now you are in deco, you don't know how much hang time you're going to have and your sharing air, so you now have a lot less than you though you'd have. Just something to think about.

 

[BoltSnap]

No, it was the tec 2g, it was sold at least from 2012-2015. Maybe still nowadays, but I don't follow Scubapro wlth computers.

It doesn't appear to be there. SP revamped/updated its computer line during the last couple of years. I haven't heard any negatives concerning their dive computer product line.

We should be getting few of these for our dive school to replace the Suuntos:

https://ww2.scubapro.com/en-GB/FRA/instruments/computers/products/aladin-sport-matrix.aspx

 

[Kharon]

I try to put the discussion back to behavior of the cheap computers (instead of my dive profile). So do they just beep and let you dive or penalize?
(@Steve_C: my current Favor-S switches to another mode if deco reaches 12 meters. It shows the arrow to come up, shows you the deco stops but not more and after requires 48 hours rest. I am not skipping any deco stops.
@RyanT: If the group starts coming up when the first guy reaches 100 bars, then there is plenty of air for the rest of the dive, including deco stops.)

It's hard to put the discussion wholly on the behavior of the computer. It looks like you are doing advanced tech dives - shallow is not 30 metres, longer bottom times, and 50-60 metres - involving deco. Don't think you are going to get an entry level computer that won't lock you out for extended periods, and/or give you continuous warnings. Entry level and the type dives you describe are incompatable IMO.

 

[RyanT]

Entry level and the type dives you describe are incompatable IMO.

This said much more succinctly what I was trying to get at.

 

[Jonny Wishbone]

Lets just say for a minute you have a family with kids (you may or may not) and one of your kids needed surgery in which surviving could go either way. Would you want the cheapest Doctor working on your kid along with all the cheapest machines and equipment? I think NOT! So flip that coin over and I bet your family and kids would not want your life to be depending on the cheapest dive computer you can get for the type of diving you do. Save your money, sell a few things or whatever you need to do and just get a Shearwater.

 

[Saboteur]

Lets just say for a minute you have a family with kids (you may or may not) and one of your kids needed surgery in which surviving could go either way. Would you want the cheapest Doctor working on your kid along with all the cheapest machines and equipment? I think NOT! So flip that coin over and I bet your family and kids would not want your life to be depending on the cheapest dive computer you can get for the type of diving you do. Save your money, sell a few things or whatever you need to do and just get a Shearwater.

That is about the lamest comparison l have ever read... sheesh.

 

[KenGordon]

Hi Guys/Girls,

Sorry if already responded somewhere (I've already spent 2 hours chechinkg through threads but did not find the answer). I am looking for information on how "agressive/penalizing" the entry level computers are when you dive deeper. Or which model would you recommend for the below dive profile and needs.

I am about to buy a new computer. I do not dive frequently (usually one safari - ca. 20 dives - per year), so I would go for a cheaps computer. Most of these dives are shallow (max. 30 meters) and in warmer seas, but there are always few with longer bottom times, or deeper dives (50-60 meters), so deco (and pO2 warning - if not counting with 1.6) comes in. As far as I could figure out so far, all these cheaper computers are fine with that, I just don't find the info about how "agressive/penalizing" they are when you dive deeper. What I expect is only a "one beep" warning and correct calculation. I would not want "continuous/unstoppable beeps" as that woul ruin that part of the dive. And no penalty should come for the next dive (of course residual nitrogen should be counted for next dive). Do these entry level computers behave like this (e.g. Mares Puck Pro)?

I do not need "extra features" like downloading dive profile or tweaking the algorithms. I do not mind if the default algorithm is on the conservative side - there is always something to see during the deco stops. My ca. 20 years old Suunto Favor-S (which was the cheapest the time I bought it) did the thing very well, but each time it is more and more risky that it will not survive (i.e. sink in after) the replacement of the battery, which is needed now. Its only limitation is that when deco starts at 12 meters, then it gives a 48 hours "no dive" penalty, but that's OK, you need repeated deeper dives for that which I do not plan to do anymore. I am looking for something similar in behavior.

Thanks in advance for your replies.

I have taken my Zoop to 56m. On that dive it bent at 7m as it thought I was on air while I was on various deco gases. The only times I have bent it have been using it as a backup doing accelerated deco. I have also used it on many deepish (40 ish) dives doing backgas deco and it is absolutely fine. I have used it on multi week holidays doing up to 5 dives in a day (although not every day) and never bent it.

I have a HelO2 which behaves almost identically on the same gas. So for backgas deco they will show the same stops.

Using DM5 you can easily plan your deco dives with these computers. You ought to do that, especially if the surface interval is less than two hours. However it is probably best to avoid deco dives so close together, especially if decoing on air.

I don’t know about the other brands, some of them do have explicit warnings in the manual, and I don’t know if any have proper planning software.

Personally I’d be inclined to get a computer which can handle a gas switch so as to allow accelerated deco. Some of the Aqualung ones are still a reasonable price, although planning ahead of time may be an issue. There are ways around that by keeping to a max TTS but I’d probably be up for a stoning at the hands of SB if I suggested that.

 

[Jonny Wishbone]

That is about the lamest comparison l have ever read... sheesh.

Youre right,,,I should have dumbed it down a bit so everyone could understand it. My bad....

 

[AdivingBel]

Youre right,,,I should have dumbed it down a bit so everyone could understand it. My bad....

No, that was just about dumb enough...FFS

 

[CandiveOz]

When I decided to upgrade my Tusa IQ750, like you, I didn’t have a big budget so I decided to look into the secondary market to get the biggest bang for my buck. Eventually I upgraded to an air integrated Galileo Sol with heart rate monitor and I couldn’t be more happy with my decision. So I encourage you to consider the used computer market.

The issue with the lower range computers, like my Tusa, is that they are really geared towards NDL diving. Even the Tusa manual discourages you from making decompression dives. The dive planner on the computer is rudimentary and only lists NDL times for each depth unlike my Galileo which allows you to plan deco dives. The Tusa dive log software also does not have any deco planning function unlike Suunto and its DM5 as mentioned by @KenGordon. If you are considering a Suunto, download DM5 and have a play. It certainly helped me gain a better understanding of the Suunto computers and the different varieties of the RGBM algorithms developed by the company. As @KenGordon mentioned you can buy the cheapest Suunto on offer – the Zoop and still be able to plan deco dives for it on DM5.

I am looking for information on how "agressive/penalizing" the entry level computers are when you dive deeper. Or which model would you recommend for the below dive profile and needs.

For me, the only way to work out deco profiles on my Tusa was to build a pressure chamber. I was then able to put the computer into deco without actually going into deco myself. This is the only way I was able to determine what deco profile would be generated by the computer. And a chamber will answer your question above.
Building a Transparent Pressurize cylinder

Finally, for any computer you are considering, download the manual and read it. This will help you determine if the computer meets your needs. For you, deco planning would be a requirement either on the computer itself or via desktop software. Off the top of my head, another brand to consider is Mares; specifically the non-air integrated Quad (It’s cheaper than the air integrated one). It does have deco planning on the computer itself and may be within your price range.

If you are interested in my personal journey of upgrading my dive computer, you can find it here. Good luck.
Algorithms, Conservative Factors, Altitude, Planned Deco - Questions