How penalizing are cheaper computers at "deeper" dives

[zoli72]

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.

 

[Steve_C]

If you are getting a 48 hour no dive then you are doing something that is ticking off the computer. Are you clearing all the deco stops and doing the safety stop? Note that if you have a more conservative computer than you might be ticking it off when those around you are doing fine with theirs. I used to dive a Suunto Zoop and a Scubapro. On the second dive sometimes the Zoop was showing 15 minutes less NDL on average. Time permitting I would clear the Zoop but there were a couple times where the Scubapro stayed in NDL, safety stop was done, but the Zoop still wanted a few minutes more deco but I got out of the water. But I was not diving for a couple more days anyway. I got rid of the Zoop and now dive two scubapros.

 

[Germie]

There is a big difference between the old Zoop and the new Zoop novo.The new novo follows more or less buhlmann algoritms,b ut what exactly is a secret. The problem with suunto is that its 'Suunto fused rgbm' is a complete black box. With Scubapro you know that it is a Buhlmann-deviation, they mostley use a 8 compartment algoritm. Almost all other brands use buhlmann.
Yes you will be 'safe' with Suunto, but there is a risk of having deco under the shower. I have seen the older Zoops locked when other computers never gave problems because of some days repetitive diving. The newer one is much better, I have seen it in use during a week cavediving and 2 weeks diving in malta (up to 44m depth, over ndl and some dives with decogas), here it just locked one time.

I had 3 uwatec 2g computers, they always got problems withing warranty (150-200 dives made), the last one flooded sadly around 150 days a few weeks out of warranty. So that is a computer I for sure will not recommend.

 

[BoltSnap]

Suunto's recreational dive computers penalize the diver by cutting the NDL substantially in repetitive dives following a deco dive in my experience. They will also lockout when you miss a required deco or safety stop.

 

[BoltSnap]

I had 3 uwatec 2g computers, they always got problems withing warranty (150-200 dives made), the last one flooded sadly around 150 days a few weeks out of warranty. So that is a computer I for sure will not recommend.

Are you talking about the new Scubapro G2 computer?

 

[Efka76]

I have Cressi Newton. Paid for ir USD 270. When i was doing my TDI Deco training i had diving plan which was on mu wristplate and used 1 cressi computer as bottom timer. Another was used as in normal dive mode. I was diving at 40 m depth, computer went into deco mode (actually deco was planned). When i was ascending and doing stops accordong to my plan, deco mode fully cleared. When i ascended dive computer history showed that my last dive was in a deco. That’s it.

During next deco dive i specifically did not switch gas on one of my Cressi Newton computers. When i ascended it showed deco violation and i there was indication that i have to wait for 48 h until next dive. However, dive computer was was still working in gauge mode.

 

[Vicko]

With suntoo computers, at least from Vyper onward 48 hour lockout starts only when you miss a mandatory deco stop.
I dive my D6i to 60-70 meters a couple of times a year and since it's usually the only dive of the day I get noticeably less deco time then on my Shearwater with Buhlman 50/90.
On repeated dives it gives noticeably more deco, on some dives more than double. I also have no idea how it calculates that deco, once I had 30 minutes at 3m and after 45 minutes I gave up and locked the computer as there were still 15 minutes left.
Also the ppO2 alert is very distracting (I know that's the point of a alarm).
All the deep air divers I know dive the old Uwatec Aladin with a Sunto Vyper backup, most of those guys are going up to 90 meters and they are still alive (but bent ...)
I would strongly suggest that you get some accelerated deco training, it makes dives like those much more enjoyable.

 

[RyanT]

I agree with @Vicko, doing 50-60 meter deco dives on a computer where you don't know how the algorithm responds (e.g. diving a black-box computer) is asking for trouble. I've seen cases where a diver went into deco on their puck computer and then freaked out when it gave them a long hang and they didn't have the gas for it. If you're doing those kinds of dives, you really should have a planning software and understand what your computer is going to give you on those dives.

 

[Germie]

Are you talking about the new Scubapro G2 computer?

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. None of the 3 I head lasted longer than 150-200 dives. And in salt water it would not turn off anymore, even not after rinsing, you must put it for 1 hour or so in fresh water.

The TS writes about sportsdiving, shallow dives up to 30-40m within NDL. I have seen the old Vipers or Zoops go into '505' modus on repetive dives. The viper novo is much better then, but still can lock.
The Mares Puck is ok for a week with 20 dives within NDL. The Cosmiq also (oled screen and around 300 dollar).
Cressi Leonardo works also ok.

 

[zoli72]

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.)