Are we wrong to be different?

[Yoda-X]

Mine and my wife's birthdays are 3 weeks apart and this year we decided to buy each other a beginning dive computer. She wants the Zoop and I kinda like the Leonardo.

The million dollar questions are (no, you don't get a million for answering, unless you mean thank you's)

1) Would we be doing ourselves a disservice by having different computer "brands"
2) if we had to pick one (sorry, probably asked a million and one times) which would it be and why?

We will always dive together if that has any weight.

Very much appreciate any input from those in the know!!!!

 

[KenGordon]

There are two schools of thought:
Have the same make as then you can both understand the other perfectly and your stops, NDL etc will be the same.
Have two different ones then if one goes wild the other will not and you have a second opinion. Follow the more conservative one. Downside is you both ought to learn how the two computers work and neither of you will know exactly how far you are from the effective NDL of a dive.

As a beginner it probably does not matter, go with what you fancy. Later if diving by waiting until your ascent time is 'enough' and you discover that your buddy's ascent time is 'too much' you might reconsider. However, in those sort of dives you should really have an agreed plan to avoid such embarrassment.

 

[darrenlowjq]

1. Regarding having different dive computers, the only concern would be that the algorithms may be slightly different and therefore the NDL displayed at any given time during the dive will vary. As long as you dive to the more conservative of the 2 computers, you should be fine. I still carry the Suunto D4i that I had from before I got the Shearwater Petrel as a backup on dives and my recollection is that the Petrel seems to be more conservative when I go on deeper dives, but its not a big problem.

2. I don't have a whole lot of experience with different dive computer brands so I'm sure someone else will answer it better than I will. The obligatory scubaboard answer will be to get the Shearwater Petrel and I have one myself, so I can say that gets 3 thumbs up from me, with the nice OLED display which is really helpful especially on night dives. Their reputation for customer service is also legendary and its nice to be able to swap the battery by yourself easily. I think in the interest of possible advances in your diving career, if you don't want to start out with an expensive tech computer like the Petrel, look out for one you can also put into gauge mode. That will ensure your first computer doesn't become obsolete if/when you decide you'd like to go the tech route.

 

[Steve_C]

95% of my diving is with buddies who have different computers than I do. Not an issue. I just make sure before the dive that I can read it if a deeper dive. Personally I dive two computers on my wrist. They are different.

I would be interested in knowing what % of divers actually ever go tech. I have a hunch that it is actually not that large.

 

[dmaziuk]

1) Would we be doing ourselves a disservice by having different computer "brands"

Theoretically when you have 2 devices giving you different readings (in this case NDL), you'll need a third one for a tie-breaker. In practice our dives so far seem to be limited by the air, not NDL, so meh.

2) if we had to pick one (sorry, probably asked a million and one times) which would it be and why?

If you want to download the dives into a computer, the cable/kit is ~$100. Two of the same means only one cable.

You can get an aeris a300 from amazon for $200, it looks like a much better DC then either of those. There may be some n2itions left at Dive Gear Express, also better bang for the buck.

 

[tbone1004]

you'll be fine with those, I just wouldn't recommend either of them personally. Just understand whichever computer hits NDL's first will be when the other has to come up.

https://www.divegearexpress.com/zeagle-n2ition-3-gas-dive-computer

would highly recommend that instead though...

 

[Yoda-X]

Does the Zeagle have the ability to download to a PC?

 

[tbone1004]

yes but you have to get an extra adapter for it and it's frankly not worth it. Unless you want to view the specific profiles it's easier to just have the numbers and manually log it. I certainly wouldn't pay any extra money for the download kit on any of the computers listed above.

 

[guyharrisonphoto]

Hello Yoda X,

You are not "wrong" but you may needlessly be submitting yourself to inconvenience if you have computers running two different decompression algorithms. The inconvenience is if you get one computer that is more "conservative" than the other, you are going to be stuck with the shorter NDL, because, if you violate the more conservative computer, it will lock out (unless it is a petrel or Subgravity) and you will lose the use of the computer for 24 hours.

So, you really need to have the same algorithm. This does NOT necessarily mean the same brand. Just as an example, Scubapro, Petrel, Hollis, Zeagle and Oceanic all run a Buhlman Z-16 type algorithm and so should give you pretty much identical NDLs (other brands might run Buhlman as well, these are just the examples that come to mind) and you could mix all of these brands. Some brands, however, like Suunto, Liquivision, Mares, and maybe others run their own proprietary algorithm and so cannot be easily matched to any other brand--so you would have to get two of the same brand. I do not know which algorithm the Leonardo runs, but it will NOT match with the Suunto, which has a proprietary algorithm.

However, there is an advantage to the same brand and model as it is far more convenient to have equipment that works identically to that of your buddy, so if you check their computer for any reason (or they yours), you instantly know what to do and how it works.

None of this advice has anything to do with "safety," only with convenience and consistency. There have been some comments, such as "follow the more conservative" or "it's nice to have a second opinion" but none of these principles have any known relationship to safety.

I have posted about this extensively on other threads after a lot of research, and the evidence so far shows that all algorithms in common use for recreational diving are equally "safe" in that there is no statistical evidence that one type of algorithm has any correlation to more incidents of DCS than any other type of algorithm. Thus, the very 'liberal" DSAT algorithm is just as "safe" as the more conservative Buhlman or the even more conservative proprietary algorithm in Suunto computers. So, there is no 'need" for a more "conservative" algorithm. What you want is only the same algorithm.

Also, all algorithms change how they calculate NDL in the context of repetitive diving. One that is "liberal" for a single dive or two, might rapidly become more conservative and give shorter NDLs for multiple dives over multiple days (ie, a dive vacation) where a more "conservative" algorithm might remain more consistent and not change so much. For this reason, I use a computer running Buhlman as it is moderately conservative and stays pretty consistent.

As for brands, they are all good. I think Tbone's recommendation from divegearexpress is an excellent deal on a really good computer.

 

[Yoda-X]

I just ordered one of the Zeagles so we can see how we like it. I appreciate all the input.

Yoda-X