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loudgonzo
07-25-2007, 07:56
I'm in the market for a new computer, will purchase within the next month or two. I'm not interested in pushing the limits and diving on the edge, but what I am curious about is just how much more time on average will a liberal computer give you over a conservative one diving the same profile? I hear the Suuntos are some of the more conservative computers out there, but does using one simply mean I'm going to surface a few minutes before someone using an Oceanic on each dive, or am I really going to miss out on a lot more?

Judestudio
07-25-2007, 19:43
I'm not interested in pushing the limits and diving on the edge...
I don't think any computers will try to put you in danger by pushing the limits. Even the most liberal ones would have some sort of settings for users to adjust for the liberality. Suunto is known to be quite conservative, some people like them so they know they're always on the safe side. But because Oceanic and Uwatec use a different algorithm, that doesn't make them less safe and put you in danger. As far as I know, the Suunto computers show their conservativeness more prominently when you're doing repeated dives, it makes you surface much sooner than other computers.

Choose one that fits your budget and have features that suit your diving environments.

tc_rain
07-25-2007, 20:32
One thing to remember is that you can set a liberal computer more conservative but you can't set a conservative computer more liberal.

CompuDude
07-27-2007, 12:10
tc_rain pretty much nailed it. Nearly every computer ever made can be set to dive more conservatively, if that's your preference, You don't have that option with a conservative computer. I prefer to have a choice in all aspects of my life, and won't willingly give any options up.

As far as differences are concerned, it can be pretty significant. Note that one the first dive of the day, a conservative computer and a liberal one both tend to be pretty close. On repetitive dives, however, the difference becomes rapidly clear. You can easily lose 20 minutes+ on a dive compared to your buddy doing the same dives on a more liberal computer.

I won't dive with someone using a Suunto computer on a liveaboard. (Not after the first dive of that day, that is.) You should always stick together, so the most conservative computer ends up limiting the dive. I'm not interested in having a buddy's choice in computers limit the dives I paid for.

Finally, remember this: No single computer manufacturer can point to a safety record that is any better or any worse than another's. Why is that? You would think that the more conservative computer makers would have a much better safety record that they would be touting. Yet they're no better than the "liberal" computers as far as the safety record is concerned. That pretty much seals the deal for me.

loudgonzo
07-27-2007, 12:53
tc_rain pretty much nailed it. Nearly every computer ever made can be set to dive more conservatively, if that's your preference, You don't have that option with a conservative computer. I prefer to have a choice in all aspects of my life, and won't willingly give any options up.

As far as differences are concerned, it can be pretty significant. Note that one the first dive of the day, a conservative computer and a liberal one both tend to be pretty close. On repetitive dives, however, the difference becomes rapidly clear. You can easily lose 20 minutes+ on a dive compared to your buddy doing the same dives on a more liberal computer.

I won't dive with someone using a Suunto computer on a liveaboard. (Not after the first dive of that day, that is.) You should always stick together, so the most conservative computer ends up limiting the dive. I'm not interested in having a buddy's choice in computers limit the dives I paid for.

Finally, remember this: No single computer manufacturer can point to a safety record that is any better or any worse than another's. Why is that? You would think that the more conservative computer makers would have a much better safety record that they would be touting. Yet they're no better than the "liberal" computers as far as the safety record is concerned. That pretty much seals the deal for me.

Thanks, very informative and exactly the kind of info I was looking for. I mostly wanted to see about how much time difference on average you lost between them. Sounds like the Suunto is slowly making its way down my wish list

thesmoothdome
07-27-2007, 13:26
Wow Comp, guess we won't be diving on a liveaboard together any time soon. On my last, and granted only, liveaboard experience, I didn't notice my profiles being much different from anyone else on board, nor did I have any dive cut short due to the conservative nature of my Suunto.

CompuDude
07-27-2007, 13:54
Wow Comp, guess we won't be diving on a liveaboard together any time soon. On my last, and granted only, liveaboard experience, I didn't notice my profiles being much different from anyone else on board, nor did I have any dive cut short due to the conservative nature of my Suunto.
Well, depends... how is your air consumption? ;) And there's always that first dive of the day. LOL

Depending on how deep the dives are and what the profiles are, there will always be times that air supply limits your dives more than NDLs.

Besides, there are no hard and fast rules in my diving world. I'll let you know next time I'm down in SD!

thesmoothdome
07-27-2007, 13:59
Sounds good. I'll grab a HP130 for the day, so I can hang. :smiley36:

MxDiver
07-28-2007, 14:12
I'm in the market for a new computer, will purchase within the next month or two. I'm not interested in pushing the limits and diving on the edge, but what I am curious about is just how much more time on average will a liberal computer give you over a conservative one diving the same profile? I hear the Suuntos are some of the more conservative computers out there, but does using one simply mean I'm going to surface a few minutes before someone using an Oceanic on each dive, or am I really going to miss out on a lot more?

I'm also in the market for a new computer, while researching I found this article:
http://www.scubadiving.com/article3170
It has a section on the risk vs. freedom and shows a few images with NDLs for different computers over three dives which show how much difference there is between the profiles.

deepdiver47
08-02-2007, 08:36
Wow Comp, guess we won't be diving on a liveaboard together any time soon. On my last, and granted only, liveaboard experience, I didn't notice my profiles being much different from anyone else on board, nor did I have any dive cut short due to the conservative nature of my Suunto.

Agreed, I love my Vyper. As far as it being conservative, that is a good thing. As far as it handcuffing you during a dive day because it can be conservative, not a chance.

Anyone who says that Suunto computers are not good because of this reason are bending the rules.

Wolfie2012
08-02-2007, 08:53
Agreed, I love my Vyper. As far as it being conservative, that is a good thing. As far as it handcuffing you during a dive day because it can be conservative, not a chance.

Anyone who says that Suunto computers are not good because of this reason are bending the rules.

Nobody's bending the rules. Bottom line is that conservative computers give you less time than more liberal computers before NDL is reached. That's the nature of the beast. For me, I wouldn't prefer to dive a Suunto computer because of that, which means that for me, they're not good. For others, you for example, it means a higher degree of safety, and so they're good for you. It all comes down to what a particular diver considers to be important and what they believe will bring them topside safely.

deepdiver47
08-02-2007, 08:58
Understood, I have done enough dives with my Vyper (primary) and Mosquito (backup) to have a great sense of confidence that I won't get bent (although there are no guarantees). It comes down to confidence in your equipment and your abilities.

ScubaToys Larry
08-02-2007, 09:29
I'm of the mind set that more conservative is not "better". If that were the case, I've got one of those pool alarms, so if someone falls in the water - it goes off. Then that would be the best dive computer right?

The Oceanic family of computers are modeled after the Padi tables, with a few modifications. If that algorithm was shown to be dangerous, I doubt the largest training agency in the world would still be using it from a liability standpoint.

And it is true, you can take some of them and set them down to be more conservative if you wish.

The other thing... my speedometer in my car goes to 130 - but I can drive 60 if I want. In basic simple terms - if diving a computer - don't let the big number hit zero (time remaining). If you want to be a bit more conservative - don't let it hit 5. If you want to be more conservative - don't let it hit 10.

So it is all a personal choice on which one you choose, and how you dive it - but my personal choice is have a more liberal computer, and then decide if I want to cut my dives shorter than what it allows.... Your mileage may vary. :smiley2:

BSea
08-02-2007, 09:32
One thing to remember is that you can set a liberal computer more conservative but you can't set a conservative computer more liberal.
That's not true, at least not entirely true. I have a setting on my Suunto Vytec that allows for a more liberal profile.

deepdiver47
08-02-2007, 09:36
You must already be in a more conservative mode correct?
On my Vyper I can go normal, them "+" or "++" to be more conservative

BSea
08-02-2007, 09:44
You must already be in a more conservative mode correct?
On my Vyper I can go normal, them "+" or "++" to be more conservative
On my Vytec, you can set the RGBM effects to 50% vrs 100%. I asked my LDS just how much more liberal it made the computer. The answer was "I'm not exactly sure, but it will be less conservative at 50 than at 100." That may be similar to your "+" or "++". But the default is 100, you have to go in and change it to 50.

awap
08-02-2007, 11:42
The other thing... my speedometer in my car goes to 130 - but I can drive 60 if I want. In basic simple terms - if diving a computer - don't let the big number hit zero (time remaining). If you want to be a bit more conservative - don't let it hit 5. If you want to be more conservative - don't let it hit 10.


That is where the tissue loading bargraphs are great. Backing off 10 minutes on time is so depth dependent. At 130 ft. you probably can't do the dive. And at 30 ft, 10 minutes would have almost no effect on tissue loading. But backing off on the bargraph is almost independent of depth. My older Oceanic computers give me a lot more graphic resolution than the newer ones. They have 12 ticks in the green and 3 more in the yellow. Normally I will terminate a dive if I get into the yellow and will extend my rest stops to clear a yellow tick if necessary.

So I usually manage my nitrogen loading primarily using the graph and use the NDL output to tell me how much time I have before the graph goes into the red. Those ticks can accumulate pretty quickly undeers some conditions.

deepdiver47
08-02-2007, 19:19
Then you dive using only the computer and not the tables, correct? Sounds like a naive question but that is how I dive as I use both a primary and backup computer for every dive. Can't say I pay attention to the tables much (if at all).

CompuDude
08-02-2007, 19:43
Then you dive using only the computer and not the tables, correct? Sounds like a naive question but that is how I dive as I use both a primary and backup computer for every dive. Can't say I pay attention to the tables much (if at all).
Tables get pretty useless quickly if you're doing a lot of multi-level repetitive diving.

CompuDude
08-02-2007, 19:45
The other thing... my speedometer in my car goes to 130 - but I can drive 60 if I want. In basic simple terms - if diving a computer - don't let the big number hit zero (time remaining). If you want to be a bit more conservative - don't let it hit 5. If you want to be more conservative - don't let it hit 10.


That is where the tissue loading bargraphs are great. Backing off 10 minutes on time is so depth dependent. At 130 ft. you probably can't do the dive. And at 30 ft, 10 minutes would have almost no effect on tissue loading. But backing off on the bargraph is almost independent of depth. My older Oceanic computers give me a lot more graphic resolution than the newer ones. They have 12 ticks in the green and 3 more in the yellow. Normally I will terminate a dive if I get into the yellow and will extend my rest stops to clear a yellow tick if necessary.

So I usually manage my nitrogen loading primarily using the graph and use the NDL output to tell me how much time I have before the graph goes into the red. Those ticks can accumulate pretty quickly undeers some conditions.
I would need to know more about the algorithms in use before depending on those bar graphs in that manner.

Deco theory is all about theoretical tissues and halftime nitrogen absorption rates. There is no direct tie to any given human tissues.

deepdiver47
08-02-2007, 19:46
yes they most certainly do!

jeff franks
01-25-2008, 08:04
an older thread but..
my spouse and i have been using conservative tusa computers --so it's nice that we aren't on different dive profiles but the conservative nature of our computers compared to most of the dive groups we're with does cause problems. yes we can in theory accommodate by going to less depth than the rest of the group but this can be problematic especially in drift diving which we do a lot. the currents can vary at different depths both in speed and sometimes direction--very hard to keep the group together and it feels lousy to consevatively control the dive time of others. we're probably going to get another set of computers

dannybot
01-25-2008, 19:49
I have a Gekko, my wife has a Veo 180. On out last trip, I averaged 4 dives per day to her 2.5. Only once did I have to adjust my profile because of pushing NDL's. Going a little shallower is a small sacrifice to ensure my safety. Another feature of the Suunto computers is that they actually calculate a "No-fly" rather than simply 12 or 24 hours after last dive.

Dive4Fun
02-05-2008, 17:13
Hmm, I prefer to go more liberal because I'm confident in my abilities and physical conditioning. I'm looking to get a new computer, my last one I bought based on price, now I'm looking more towards algorithm and features. Because I only have one computer I still plan the dive on tables, then follow the computer when in water. If I have a malfunction then I follow times/depths based on my table plan.