Suunto OK for liveaboards?

[mason417]

Thankyou all for some very good info plus personal experiences. This is what I was looking for when I asked this question. I am looking at buying the Vyper non air wrist model

 

[scubadada]

Cart before the horse. If you're diving thirty times in a week, how safe do you want to be?
My feeling is that all of the major companies algorithms are fine... you can generally make a liberal computer more conservative, but not vice-versa. The amount of time you spend in the water is ultimately up to you. I wonder if there are any statistics on DCS incidence vs. individual computer brands used correctly?
didn't think so...

Ultimately, DAN's Project Dive Exploration may shed some light on the issue. In the meantime, there are some mathematical estimates regarding relative risk of DCS diving various computer algorithms.

An example can be found in Table 7-6 on page 154 of Bove and Davis' Diving Medicine, Saunders, 2004. Estimates of episodes of DCS/10,000 dives to the NDL limit at 60 fsw of various computers and tables were made. All of the rates were low and they did not vary much by algorithm. The rate of one of the most conservative of computer algorithms, Suunto, was 49 episodes/10,000 dives. The rate of one of the most liberal computer algorithms, Pelagic Pressure Systems, was 68 episodes/10,000 dives. The NDL times at 60 fsw for these 2 algorithms was 50 and 56 minutes. This makes sense to me, the longer the exposure near the limit, the greater the risk. Figure 7-25 on the same page shows the estimated risk of DCS/10,000 dives at 60 fsw as a function of bottom time.

Aspendiver is generally correct, the risk of DCS using any of the commercially available computer algorithms is quite low, but it is certainly not zero for any of them.

Good diving, Craig

 

[ptyx]

On those trips, safety won't come from your computer. It will come from keeping hydrated, fed, rested, and knowing when to skip a dive.

That said, the Vyper will give you very short NDL at the end of the week if your average dive is deep. Nitrox will make him - and more importantly you - happier.

 

[RJP]

Took my Vytec DS on the Cayman Aggressor (30 dives in 6 days) Truk Odyssey (54 dives in 17 days) and a Bonaire trip (32 dives in 6 days) and never had a problem, even doing deeper/deco dives in Truk.

 

[stargost]

Mason417,
I'd get the Viper2 instead of just Viper. More features, and especially the dot matrix LCD reads better.
I'm using Gekko or Aeris manta right now, and from user friendly point of view, there is no comparison. Suunto is much easier to use.
Size is not best, but it a personal choice. And other advantage if you care: it seems the only decent software compatible with OSX.

 

[Willar]

I took my Suunto Cobra on Blackbeards cruise, 28 dives in 6 days. I didn't have any problem with short times compared to others. I found I had good NDL with 60 minute or better surface intervals, occassionally hit deco, but never got into really long stops. On trips to Bonaire, Cozumel, and others I never had a problem with limits after repeated multiple-dive days. I found many divers with Suunto and never heard anyone complain about short NDL compared to other divers. I love my Cobra and will upgrade to the latest Cobra sometime soon.

 

[ibj40]

I've been using a Suunto for years. I'm a liveaboard addict. I love my computer.

Do you really want to push the no deco limits if you're doing 3 - 5 dives a day? I don't. I don't mind the Suunto's conservative algorithm.

My hubby uses a different brand dive comupter. Sometimes he has more bottom time left than I do. He NEVER has more air left though. The limiting factor on our dives is his air, not my bottom time. It all comes out in the wash.

What I really LOVE LOVE LOVE about the Suunto is that it is sooooooo user friendly. The interface is very intuitive. Although I don't recommend it, it is possible to take the computer into the water with you for the first time without reading the manual and still know what the computer is trying to tell you. It makes every thing easy.

If you're a tech diver you might want to consider a different brand. But I really don't think anything can beat a Suunto for the average rec diver.

Great insight!

I dive a Cobra 2 and my wife dives an Atmos Aeris, and hers is a lot more forgiving than mine, and what I've found is that I have to be cognizant of the computer, and profile up a little sooner than she does. Fortunately our air consumption is compatible, with her's being a little better. Usually as he head up for the safety stop, I'm already starting to count down before she gets up to 15', so we both clear about the same time.

And I'm almost 60, used to run marathons, and still appreciate the conservatism of the computer.

 

[Damselfish]

I've always had Suuntos and they have never limited me on a liveaboard. I would suggest getting certified for Nitrox if you haven't yet though.

A little conservative isn't necessarily a bad thing when doing 5 dives a day in a remote place, anyway.

 

[Bubbletrubble]

An example can be found in Table 7-6 on page 154 of Bove and Davis' Diving Medicine, Saunders, 2004. Estimates of episodes of DCS/10,000 dives to the NDL limit at 60 fsw of various computers and tables were made. All of the rates were low and they did not vary much by algorithm. The rate of one of the most conservative of computer algorithms, Suunto, was 49 episodes/10,000 dives. The rate of one of the most liberal computer algorithms, Pelagic Pressure Systems, was 68 episodes/10,000 dives. The NDL times at 60 fsw for these 2 algorithms was 50 and 56 minutes. This makes sense to me, the longer the exposure near the limit, the greater the risk. Figure 7-25 on the same page shows the estimated risk of DCS/10,000 dives at 60 fsw as a function of bottom time.

@scubadada: Thanks for the statistics from Bove and Davis. The numbers raise a bunch of questions, though...specifically regarding how the data were collected. Although one might be tempted to conclude that Suunto computer users have a lower relative risk of DCS than Pelagic users (due to differences in the algorithm used), a deeper look into the numbers might prove surprising. I think we can all acknowledge the importance of minimizing bias in the study population -- specifically with regard to age, gender, pre-existing medical conditions, aerobic shape, dive profile specifics, etc.
Along these lines, a skeptic might pose the following questions:

• Did the divers included in the study "ride the NDLs" or did they dive more conservatively?
• On a similar note, did they all dive a specified profile? If so, how closely did they adhere to the designated profile?
• Were dive computers randomly distributed to study participants? (If there's a perceived notion that Pelagic computers are more liberal, then is it possible that more "aggressive" divers gravitated to that brand?)
• Were all computers set to the most liberal setting?

One can easily see how any of these flaws in experimental design could affect the results. In fact, I really wouldn't be surprised if a properly controlled study demonstrated no significant difference at all between the groups.

[soapbox]
As a scientist, I know that it's easy to "fall in love" with the data when they appear to support our hypothesis (in this case, that a diver using a more conservative dive computer will have a lower incidence of DCS). I submit, however, that drawing any conclusions at all from a poorly constructed study is foolhardy.
[/soapbox]

Just my 2 cents...

P.S. I really do appreciate the fact that Craig went to the trouble of sharing the data with us. I realize that this post might be slightly off-topic, but hopefully some people out there will find it informative.

 

[Texasdivechick]

Statistically, I can't provide sound data on the experience that me and my dive buddies all shared with the Suunto vs. other computers, but I can give an anecdotal description. While on a dive trip with 9 of my friends (who are all fairly similar in experience, age, and dive profiles) we did two dives on the Speigel Grove. We all were back on the line (ripping current that day) at roughly the same time, give or take a minute or two. We moved up incrementally and slowly from a depth of about 30 fsw to 15ft on a safety stop. Even though I was at the anchor line before some of my friends and ahead of them in line to exit the water, I was unable to ascend because I had gone into deco. There were 3 of us diving Suuntos on the trip. Through hand signals we were able to determine that only the Suunto divers went into deco. My primary buddy who was diving a Nitek Duo did not. This was confirmed when we finally all were back on board and checked our Suunto computers against the others. This isn't necessarily a bad thing, but it was an odd coincidence (due to the conservative algorithm?). Can this example be scientifically validated? No, but it does create some interesting conversation back on the boat after the dives and here on SB.
Thankfully, my dive buddy didn't mind hanging out with me for an extra 4 minutes while I fulfilled my deco obligation. We both had plenty of gas left and weren't in any hurry to leave the water anyway.