Suunto Zoop or Aeris A300

[stuartv]

Maybe I misunderstood. I interpreted what you said as referring to a scenario where a diver uses a computer for maybe a few years, then buys a new ("more sophisticated" as you put it) computer when he decides to do "advanced recreational diving," and that this so-called "advanced recreational diving" is likely to result in exceeding the no-deco limits of the old computer if used as a backup to the new computer.

Nope. You did not misunderstand. So, I apologize and acknowledge that, looking at it that way, yes, I did suggest that the diver may choose to exceed NDLs down the road. And I still term it recreational diving.

And here's why:

If you click the second link I posted above (here it is again, for your convenience: http://www.scubaboard.com/forums/co...-you-want-buy-new-computer-4.html#post7378321), you will find, among other things a link to this study of a number of modern recreational PDCs:

http://www.scubaboard.com/forums/re...cubaLab-Computer-Test-September-2014-data.pdf

That study uses a hyperbaric chamber and 13 (I think) current PDCs to simulate doing 4 actual dives. The dive profiles are all "recreational" dives. Being that 3 of them go to somewhere between 70 and 100', you might term them "more advanced recreational" dives.

If you look at the data - which you are free to term "spotty" if you like - it shows that, for example, on Dive 2, after a total dive time of 36 minutes, and at a current depth of 40', the Mares Icon HD says the diver has 7 more minutes of NDL, while the Sherwood Amphos Air, the Aeris A300 CS, the Liquivision Lynx, and the Oceanic ProPlus 3 all say the diver has 48 or more minutes of NDL time left.

So, from what you have said, staying longer than 7 minutes and exceeding the NDL of the Mares, even though you may be using an Amphos Air, is "no longer recreational diving." I am a rank newb, yet I would still disagree with you. Is staying down longer less safe than staying down shorter? Yes. But, I also believe that when 4 different dive computers tell you you still have 48+ minutes left before your NDL, then it is as safe to stay down for longer than 7 more minutes as any Rec diving is ever likely to be.

Dive 3 of that same study ends with the Cressi Leonardo showing 2 minutes to the NDL while other computers are showing over 50 minutes left. If the diver is wearing a Leonardo and a Cobalt 2 and chooses to follow the Cobalt and stay longer than what the Leonardo says, again, I would still absolutely call that recreational diving.

Just like I would say if the diver were wearing a Zoop and a "more sophisticated dive computer" and the Zoop said they were past NDL and the other did not. If the Zoop says you're in deco and your Oceanic Atom or Sherwood Amphos says you still have 20 minutes of NDL left, and you're in open water, at recreational depths, then that is still a recreational dive, in my book. Maybe that's just my inexperience talking, though.

And, to get back to my point that you seem to want to argue with, it IS appropriate for anyone shopping for a computer, new diver or well-salted, to understand the algorithms of the computers they are looking at and how the implementations of those algorithms COULD affect the diving they want to do, immediately and down the road. And, people who tell a diver, "don't worry about the algorithms. I have a computer that people say is conservative and it has been just fine for me. Even the most conservative will be just fine for you," are doing that diver a serious disservice. Your values are YOURS. Give people actual data and let them decide for themselves what characteristics are of value to them.

How many threads have there been, here and in the Classifieds, that boil down to "my Leonardo is too conservative for me. I want something different"? The Leonardo is, according to the (spotty, so you say) data, a VERY conservative DC. Now, how many of that same kind of thread have you seen about an Aeris, Oceanic, or Sherwood computer - which are among the most liberal DC brands? I sure haven't seen any, actually. But, I'm new and ignorant, so maybe I just haven't seen those threads and my view is skewed by statistically invalid sampling.

 

[Lorenzoid]

When I said "spotty" data, the ScubaLab test from Scuba Diving magazine and others like it that have been done are exactly what I had in mind (since the same topic has been discussed ad nauseam in SB threads). I subscribe to that rag, and I read the article when it came out. I think you place too much weight on it. It's an interesting read, but the conclusions are still based on a limited amount of data. I think tests like that can give one a general idea of where a computer falls on the spectrum of liberal to conservative, but unless one follows those exact profiles that were tested I don't think it can be guaranteed that a supposedly "liberal" computer will in every instance compute a higher NDL on repetitive dives than some other computer.

Just like I would say if the diver were wearing a Zoop and a "more sophisticated dive computer" and the Zoop said they were past NDL and the other did not. If the Zoop says you're in deco and your Oceanic Atom or Sherwood Amphos says you still have 20 minutes of NDL left, and you're in open water, at recreational depths, then that is still a recreational dive, in my book. Maybe that's just my inexperience talking, though.

Then maybe I DID understand correctly. In the context of this thread, I believe we're considering a hypothetical situation in which the OP went against your advice and bought a Zoop and has been happily using it as his primary computer for a few years when he decided to get a "more sophisticated computer" and use the Zoop as his backup. (You're arguing not to buy a Zoop for the reason that it won't make a good backup, right?) So now he says it's okay to no longer follow the Zoop that he faithfully has been following for the last few years because his "more sophisticated" computer tells him he's going to be okay? I just see the logic as inconsistent.

And what is this "more sophisticated" computer anyway? A true technical computer like a Shearwater Petrel, where the user can set gradient factors to anywhere between ultra-conservative and "there's a real likelihood of getting bent if done as a no-stop dive"? Making those kinds of calls takes it outside what I see as the realm of recreational diving. Others may disagree.

And, to get back to my point that you seem to want to argue with, it IS appropriate for anyone shopping for a computer, new diver or well-salted, to understand the algorithms of the computers they are looking at and how the implementations of those algorithms COULD affect the diving they want to do, immediately and down the road. And, people who tell a diver, "don't worry about the algorithms. I have a computer that people say is conservative and it has been just fine for me. Even the most conservative will be just fine for you," are doing that diver a serious disservice. Your values are YOURS. Give people actual data and let them decide for themselves what characteristics are of value to them.

I would never advise a diver not to make an effort to understand the algorithms. I think understanding the algorithms, to the extent it's possible, is a great idea. I'm just not sure it is the most important factor in choosing one's first dive computer.

I have not advised anyone to get a supposedly "conservative" computer over a supposedly "liberal" computer (say, following the ScubaLab conclusions). If you hadn't beaten me to it, I was going to add that you seem to be imposing YOUR values on others. You seem to strongly advocate getting the most liberal computer possible. How many computers do you actually have experience diving with--and I mean over many dives, not just trying one out for a dive or two? Do you know for a fact that any of the computers you seem to demonize as too conservative would have impacted your dives? I have never seen anyone had to sit in their hotel room in Cozumel because their computer was too conservative. The divemaster is as likely as anyone else to have a conservative computer. Better make sure your buddy doesn't have a conservative computer, either, or you'll end up having to surface along with him, despite your liberal computer. And then there is the whole argument about air consumption being the limiting factor for most newer divers, which, like the rest of this, has been discussed numerous times in numerous other threads.

How many threads have there been, here and in the Classifieds, that boil down to "my Leonardo is too conservative for me. I want something different"? The Leonardo is, according to the (spotty, so you say) data, a VERY conservative DC. Now, how many of that same kind of thread have you seen about an Aeris, Oceanic, or Sherwood computer - which are among the most liberal DC brands? I sure haven't seen any, actually. But, I'm new and ignorant, so maybe I just haven't seen those threads and my view is skewed by statistically invalid sampling.

How many threads have there been that boil down to "I enjoy my Leonardo just fine"? There will always be more threads where someone brings up an issue that bothers them than threads where someone randomly posts nothing more than that he's been satisfied with his present computer. "Hi everyone, I just thought I'd post a thread to say that I have been diving with a Leonardo and I have no complaints. Bye." You're not going to see anyone post that.

There are thousands of people around the world happily diving the computers that get bashed on SB by the relatively few complainers as being too conservative. Suunto is an exceedingly popular brand. I don't own stock in Suunto (and though I'm currently selling a Zoop, I'm continuing to use a D6), but it just bothers me when someone advises a new diver to choose a computer based on giving a lot of weight to these conservative versus liberal tests over other considerations, such as ease of use, user-replaceable battery, display quality, customer service reputation, etc. Suunto may not do well in some of these categories, but if I were to remove Suunto from the candidate list in my search for a computer, it would be due to those and not to some judgment that it is "too conservative."

 

[DiveNav]

I can buy one for relatively the same price right now and I was wondering which one of these would be better for someone as their first ever dive computer?

They are both good entry level dive computers. We have simulators and classes for both.

Whatever model you end up purchasing make sure you learn how to properly use it.

 

[stuartv]

Man, you sure do like to put words in my mouth.

...
You're arguing not to buy a Zoop for the reason that it won't make a good backup, right? Yes. I said it lacks Gauge mode, so I would go for the other. I said it also MIGHT have limited value if he gets a more liberal computer to be his new primary.) So now he says it's okay to no longer follow the Zoop that he faithfully has been following for the last few years because his "more sophisticated" computer tells him he's going to be okay? I just see the logic as inconsistent. How? The consistency is "do not exceed the limits your computer tells you" and "know your computer's algorithms, so you can make an informed decision about which computer to follow."

And what is this "more sophisticated" computer anyway? Some examples: Ones with Gauge mode. Ones with a choice of algorithms.

I would never advise a diver not to make an effort to understand the algorithms.

Earlier, you said "There is no magic computer that gives one "longer bottom times" without any additional risk." What is that if not discouragement from worrying about the algorithms? If it's not discouragement, it is at least using FUD to steer him towards a more conservative computer - instead of steering him towards solid info on algorithms and letting him decide for himself. "If you go with a more liberal conservative it's RISKIER!" Crikey! That is total FUD to a new diver.

I'm just not sure it is the most important factor in choosing one's first dive computer. I never said or implied that is the "most important". I said that Gauge mode would be more important, to me, and that the algorithm is A factor to consider. That, in no way, means that I'm saying it's the most important. In fact, "most" or "least" would imply me putting MY value on it. Which I'm not. The OP should decide what value the algorithm is to him. I'm just saying it's worth considering, even if you decide it is even less important than the color of the strap.

I have not advised anyone to get a supposedly "conservative" computer over a supposedly "liberal" computer (say, following the ScubaLab conclusions). You have advised there is no magic bullet, implying that he shouldn't worry his pretty little head about. He should just remember that it's more RISKY. If you hadn't beaten me to it, I was going to add that you seem to be imposing YOUR values on others. You seem to strongly advocate getting the most liberal computer possible. Nope. I advocate being aware of what you're buying and the ramifications of your choice. I have no problem if an informed consumer decides that conservative is fine for them and they are partial to the Suunto brand, for example. My only "problem" is trying to help people make an informed decision, rather than an uninformed one - which results from people asking about computers and "experts" telling them that it doesn't really matter what algorithm they get as even the conservative ones are just fine - i.e. that there are no "cons" to a more conservative computer. That is a value judgment which I think is inappropriate for you to make.

...

Do you know for a fact that any of the computers you seem to demonize as too conservative would have impacted your dives? It's not JUST about how it works for you, me, or the OP today. It's how it will work down the road, when more experience and skill is acquired. Personally, I have not been limited by a computer's NDL yet. But, I have only dived with Aeris/Oceanic family computers, which seem to be on the liberal end. And I have come within less than 10 minutes of my NDL on those. I don't KNOW if a "conservative" DC would have limited me or not.

I have never seen anyone had to sit in their hotel room in Cozumel because their computer was too conservative. Here's a thread where the OP did not have to sit in their hotel room, but he does complain about having to get back on the boat well before everyone else is ready because of how conservative his Leonardo is.

http://www.scubaboard.com/forums/co.../492111-cressi-leonardo-too-conservative.html

...

How many threads have there been that boil down to "I enjoy my Leonardo just fine"? There will always be more threads where someone brings up an issue that bothers them than threads where someone randomly posts nothing more than that he's been satisfied with his present computer. "Hi everyone, I just thought I'd post a thread to say that I have been diving with a Leonardo and I have no complaints. Bye." You're not going to see anyone post that.

True. But, I wasn't comparing complaints to "I likes". I was comparing complaints about one kind to complaints about another. When you see lots of complaints about X being too conservative and no complaints about Y being too conservative, then that MIGHT be because X is actually too conservative (to make its users happy).

To repeat what I have been saying all along:

1) I would eliminate the Zoop from my shopping list because it has no Gauge mode. But, as I said before, if you're only ever going to be a recreational diver, who only ever carries one computer, then this is not a reason for YOU to drop it from your shopping list.

2) I would read the available information on algorithms and factor the pros and cons into my buying decision based on how important that is TO ME. As the OP should do for him or herself.

3) I would consider the scenario - which is OFTEN put forth here on SB, by much more experienced folks than me - that the first computer a diver buys may give them additional "mileage" later if they buy something that will work for them as a backup later. And if you're going to use a computer as a backup later, having it be equally or more liberal to the computer you buy later will be more convenient (and functional) than if it is more conservative and you end up only really being able to use it as a depth gauge and bottom timer backup to your primary computer. That, of course, assumes you carry the backup with you on all dives, so it always knows your tissue loading, in case your primary dies. If you are going to leave it on the boat until your primary dies, then you'll want (but not need) it to have Gauge mode (otherwise, ignore the NDL it says and use tables, the depth displayed and the elapsed dive time displayed) in order to continue diving that day. And then go back to using it as a normal DC the next day (after 24 hours SI), and the difference in algorithm won't matter.

---------- Post added April 20th, 2015 at 05:27 PM ----------

Oh, and:

4) I did make the observation that if you are concerned about a computer being more liberal than you want, you can always (for all the ones I know of, anyway) set it to use a more conservative algorithm and/or set it to use a higher Conservative Factor. Thus, one computer being more liberal than you want is not necessarily a reason to eschew it.

 

[Lorenzoid]

Let's put the Gauge Mode issue aside. I DO agree it's a nice feature to have. The first point I made was simply to point out that a computer without a true Gauge Mode can still be used to do exactly what a computer with a Gauge Mode does: display your depth and elapsed time. But if it came down to all other factors being equal, sure, get the one that has a Gauge Mode over the one that lacks it. I don't think lack of Gauge Mode should make or break the decision any more than choice of algorithm. Both are factors I would recommend taking into consideration but not giving undue weight over other factors. I would wager that the vast majority of divers who have Gauge Mode on their computers never use it. Scubaboard is not the entire world, and the vocal ones on SB who think Gauge Mode is a critical feature to have because they have moved into technical diving are not the majority. I could be wrong, but I would bet money on it.

Gauge Mode and the issue of conservativeness are different issues.

As for putting words in your mouth, you said this:

Also, even if you don't move on to technical diving, but you do move on to more advanced recreational diving, you may find that a computer that you buy now, that has a particularly conservative algorithm and also does not have Gauge may still be of little value later, as a backup computer.

This bit about the lack of value of a computer "that has a particularly conservative algorithm" as a backup computer when one later buys some other "more sophisticated" computer that is supposedly more suited to what you call "advanced recreational diving" is what motivated the bulk of my reply. No words put in your mouth. I still don't know what is "advanced recreational diving" and how one knows when they have crossed the line from regular recreational diving into advanced recreational diving. Advice to eliminate as candidates all but the computers that one thinks (based on a few published articles) are the most liberal, so that the chosen computer might have extra value as a backup if one someday does this "advanced recreational diving" with some other "more sophisticated" computer that is somehow more suited to "advanced recreational diving" just doesn't make much sense to me.

There is little "solid info on algorithms" that the OP can benefit from. Some algorithms are proprietary, like Suunto's. Comparing them, the way Scuba Diving magazine and others have attempted to do is at best a rough attempt to do what we'd all like to do. And on that note, another thing we would all like to do is get more bottom time without additional risk. You characterized my comment on that as advising the OP to get a conservative computer, but my intent was simply to stress to the OP that you cannot offer him a magic bullet. Your enthusiastic advice here could be interpreted as telling someone "hey, this is the secret to getting more bottom time." Do you have a perpetual motion machine, too? Nothing comes without some cost--at least theoretically speaking, since there is no way to know just how much more likely (if at all) one is on any given dive to get bent from having stayed down that extra five minutes. Yes, computer conservatism is one factor out of a number of factors--most of which are not in your control--that affect how long one's dive might be, and yes, computer conservatism can be roughly gauged by looking at some of those studies like the ScubaLab one.

As you point out, one can set most computers to bump up the conservatism. I suspect most people, especially young, healthy people, do not avail themselves of that feature. Most people naturally leave it set to the default, which is usually either the lowest conservatism setting or a middle setting.

 

[cbm32]

" Do you know for a fact that any of the computers you seem to demonize as too conservative would have impacted your dives? I have never seen anyone had to sit in their hotel room in Cozumel because their computer was too conservative. The divemaster is as likely as anyone else to have a conservative computer"

Cozumel? No. But I did see a diver have to sit out a day of diving in Fiji due to her conservative computer locking her out. She was livid....but when you are on a remote island where there there is only one resort/dive op, you have a hard time diving if they wont let you on the boat.

I dive a Gekko. It is my understanding that the Gekko is a pretty conservative computer and so I set it to some of the more liberal settings it offers. By doing so, I accept that I have chosen to, at times, exceed the NDL limits that would be inherent with setting it to it's most conservative settings. Even at that, I often find myself having to dive a slightly different profile than others I am in the water with in order to not exceed NDL's (or I do the deco obligations). I look at doing either as a form of "informed consent".

 

[Arsalan Ahmed]

" Do you know for a fact that any of the computers you seem to demonize as too conservative would have impacted your dives? I have never seen anyone had to sit in their hotel room in Cozumel because their computer was too conservative. The divemaster is as likely as anyone else to have a conservative computer"

Cozumel? No. But I did see a diver have to sit out a day of diving in Fiji due to her conservative computer locking her out. She was livid....but when you are on a remote island where there there is only one resort/dive op, you have a hard time diving if they wont let you on the boat.

I dive a Gekko. It is my understanding that the Gekko is a pretty conservative computer and so I set it to some of the more liberal settings it offers. By doing so, I accept that I have chosen to, at times, exceed the NDL limits that would be inherent with setting it to it's most conservative settings. Even at that, I often find myself having to dive a slightly different profile than others I am in the water with in order to not exceed NDL's (or I do the deco obligations). I look at doing either as a form of "informed consent".

I remember reading that with the suunto, if it does lock you out, you could take the battery out and put it in and the suunto would get unlocked. not sure if it is wise to do that or not but still ...

 

[Lorenzoid]

No computer will lock you out if you simply do what it tells you to do. If you ignore the computer telling you to stop during your ascent, then yes, it might consider that dangerous and lock you out to presumably discourage you from diving again for something like 48 hours. Like many of us, I think the "lockout" thing is a stupid "feature," but it need not be something to worry about.

See DiveNav's post above, advising that whatever computer you ultimately choose, please learn how to use it properly. If you do, you will not have to suffer the dreaded lock-out.

 

[SouthSideScubaSteve]

I've always heard that Suunto's algorithms are conservative, but I just did 17 dives over basically 4-1/2 days and never had an issue with NDL's.... I guess there are advantages to being an air-hog :shocked2:


That aside, the "conservative" verses "liberal" algorithm debate is probably moot for you at this point, but if you think you may ever get a second computer, you will probably want them to have similar algorithms and therefore you need to think about it now .....

DO your research, and not just on internet forums, talk other divers and to a few of your LDS's ...

Good luck!

 

[rsingleton]

I can buy one for relatively the same price right now and I was wondering which one of these would be better for someone as their first ever dive computer?

OP if you choose to go A300 route. I have one for sale. 5 months old. barely used. still warrantied.. Just need the extra money is reason i'm selling.