My dive computer is too conservative, what can I do ?

[Germie]

Strange you have too much conservatism with the Novo. The old zoops got deco under the shower.
I own a D5 from Suunto, a great price I won. But the first stopped working during a dive and showed under water: fatal system error, contact your suunto dealer.
It had warranty, so I did. I got a new one, BUT, and that is what I really don't like from Suunto: they did not give me a new screenprotect which was sticked on the broken one. And they also give me only a new computer with the used wristband. The band ok, but no screenprotector is what I really don't call any good customer service.

But ok, my second D5 is running. I have taken it together with my Shearwater to several dives. The shearwater is dived in 40/75. The suunto I did not adjust, so it will be the '0'. On most single dives, the Suunto shows more NDL than the Shearwater.
But if you get into deco with the Suunto, it is running up faster than with the shearwater.
Sometimes, you see some strange things when you are doing cavedives for example.
If you stay a long time around 12m, the Shearwater counts deco back. The suunto count deco up, so you get more deco. After a long dive with only ean32 as gas, and a max depth of 26m, both had the same deco, but this was due to the long time at 12 Suunto did not like.

But if you do just single tank dives and most are within NDL, the Suunto D5 is not reacting too conservative. I have tested this also on air dives, 4 per day in Bali, together with the Shearwater on air, 40/75, BO modus (I am too lazy to set it back to OC tec, I never found differences, even the manual states this is not the right way).

I have had students with the old Vipers and the Novo. The older ones got the '505' during dives, the newer ones not. The older ones really got deco under the shower as we call it.
The newer ones seems like to follow a 80 or so as GF-high if you use a Buhlmann as second computer. Suunto uses 'fused RGBM', but they tweaked it for sure in the Novo computers. And it looks like more a gf-high80 profile in shallows.
On dives up to 65m ( I haven't been deeper with my D5), I have not seen too long decos with the D5. But sometimes a deeper first stop than Shearwater gives. The only thing is, don't ignore it with Suunto, you will get the '505', instead of a recalculation which Shearwater does.

I have other requirements for computers than most recreational divers have, so most times the Novos are ok to use, together with the Pucks and such stuff. Recreational divers normally don't need recalculations for missed stops. But this is a big miss in my eyes in the D5, which is a semi technical computer (only does nitrox, but you can use a decogas, but sadly not change under water if you forgot a gas to put in).

So if your Novo is reacting strange, I would advice to borrow a second Novo from a divecenter or a buddy and see if same happens.
Are you diving strange dive profiles? Then a Suunto can react strange. Are you bouncing a lot? Look also at this. I have seen that Suunto can react different than Shearwater on such dives.

And if you still have a too conservative computer, buy another one. The mares Puck Pro is a good cheap one for recreational divers. The Shearwater Petrel or Perdix is of course top of the notch. But normally the Novo is not bad or too conservative.

 

[stepfen]

Welcome to ScubaBoard @Ben0102.

If your target is longer NDL times, then I have the perfect solution for you: dive with NO dive computer and stay underwater as long as you can.... Problem solved (?)

Now seriously. The road trying to get 1-2-3-5-10 minutes extra NDL is VERY slippery.

We need to understand that:
- The fact that diver X has done 100s of dives with his/her liberal DC and didn't get a hit, means nothing much about how many dives I or you can do with the said DC before we get a hit as there are numerous other factors affecting this (PFO, age, obesity, fatigue, dehydration etc etc etc).
- There have been numerous DCS incidents even well within NDL limits of conservative DCs.
- No matter how conservative or not our DC is and no matter how many NDL minutes it says we still have there is only one fact: the more we stay deep underwater, the more our chances of DCS increase.
- At the end of the day what is it down at 100feet that worths being seen for the extra ~5 minutes (usually that is the amount of NDL differences we see), that can't be seen say at 50feet??
- I don't know for you, but I don't want to see what color recompression chambers have from the inside and I have decided that nothing down there deserves the extra 1-2-5-10 minutes of admiring compared of finding out the color of the recompression chamber's walls.
- For me conservatism of these DC is a good thing (I've been diving with a Cressi RGBM similar to Suunto for some years) especially for new divers (like the OP according to his profile) that don't fully understand the risks. After some years of diving, I switched to Buhlmann (Peregrine and Ratio iX3M2). Not for the longer NDL times (quite often Buhlmann gives lower NDL compared to RGBM as @Germie said above) but for the flexibility (GF) and extra info (SurfGF, GF99) they offer (at least the Peregrine).

If you want so much to extend your bottom times SAFELY there are much safer and proven techniques out there than changing your DC. These include use of EAN to begin with and if this is not enough for you, multiple gases for accelerated deco etc. Yes they are a bit more complicated (extra training and eventually extra equipment), but that's the safest way ahead.

My 2c as always. All the best and again welcome to scubaboard.

 

[Ben0102]

The problem is that you have no idea what the propriety algorithm is doing. It’s probably safe to assume that your Zoop doesn’t have the computational power to actually run RGBM, so maybe a dissolved gas model with some RGBMish tweaks? In any event, you’re playing a guessing game with high stakes.

that is, in fact, helpful

 

[inquis]

Multi-level is the way to go. [...]
Set the computer to gauge mode and use PADI table.

Tables are even more conservative on multi-level dives than RGBM.

 

[Centrals]

Tables are even more conservative on multi-level dives than RGBM.

I should had said PADI's "WHEEL".
Pity the device is longer being taught for many yrs.

 

[inquis]

I should had said PADI's "WHEEL".
Pity the device is longer being taught for many yrs.

They upgraded the user interface a while back. Feedback has been overwhelmingly favorable in spite of the price increase.

 

[Streydog]

Hello hello,

Here's my problem. I've just bought a Suunto Zoop Novo, but I realise that the algorithm used is on average significantly more conservative than that of the dive computers of the people I dive with (for example Aqualung). I'm not at all in favour of excessive risk-taking, but I'm thinking more and more that Suunto's conservatism isn't really justified, since other computers allow longer NDLs at the same depth (again, I'm thinking in particular of Aqualung), and yet they're widely used by dive clubs all over the world, without causing a significantly higher number of accidents (tell me if I'm wrong on this point). I realise the same thing when I compare the NDL given by my Suunto with the PADI dive tables, which are also more liberal.

I'd also like to stick with my dive computer as I like everything else so much.

I was thinking of a solution that would allow me to slightly reduce the conservatism of my computer: set it to an O2 level slightly higher than the one I actually use (Nitrox 25% if I dive with air, for example), so as to obtain results close to the PADI dive table when I plan my dives with the computer.

Is this taking a risk? What could be dangerous?

Thx a lot for your responses !

I have used a Vyper Novo as my primary and a Geo 2.0 as a back up for atleast the last 200 dives. I know this isnt ideal but it's what I have and I use the Vyper for AI.
Sure the Geo gives me more bottom time but the Vyper does not hold me back. I have used it on a LOB with 25 dives in 5 days. I have used it with 120's is Cozumel, averaging 85 minute dives the last three trips. The key is using nitrox for repetitive or deeper dives.
I had one of those know it all guys on a boat in Cozumel make a smart ass comment about me using a Sunnto and how it will effect the dive time. After the dive he was just bitching about his ankles getting stung while he was laying on the bottom taking pictures.
You will be fine with your Zoop

 

[PatW]

I had a Suunto years ago. It was pretty in line with other computers for the first dive. On the second dive or third dive it would often force me up because of lack of deco even though my dive buddies were fine. And I typically dove shallower then they did.

 

[tridacna]

I start

So the D4 is now in my dive bag as a back up, when my Teric breaks during a week long liveaboard diving in the middle of no where.

How does the D4 help in your dive bag? Shouldn’t it be on your wrist or in a pocket?

 

[GreggS]

I have used a Vyper Novo as my primary and a Geo 2.0 as a back up for atleast the last 200 dives. I know this isnt ideal but it's what I have and I use the Vyper for AI.
Sure the Geo gives me more bottom time but the Vyper does not hold me back. I have used it on a LOB with 25 dives in 5 days. I have used it with 120's is Cozumel, averaging 85 minute dives the last three trips. The key is using nitrox for repetitive or deeper dives.
I had one of those know it all guys on a boat in Cozumel make a smart ass comment about me using a Sunnto and how it will effect the dive time. After the dive he was just bitching about his ankles getting stung while he was laying on the bottom taking pictures.
You will be fine with your Zoop

I, too, have used the Vyper Novo in the past. I actually did like it, especially the screen layout, and only had a couple of times when I had to surface a little earlier than I thought I should due to NDL. I switched to an Oceanic OCi a couple of years ago for 2 reasons: the transmitters will work with multiple DCs across different brands and because I found a great deal on a used one with the transmitter. My granddaughter now uses the Vyper Novo.

But one thing I have noticed in places like Coz, Roatan, Fiji, and other areas with guided dives is that a great number of the DMs wear Suuntos, which if you think about, is smart. Being that it is considered one of the most conservative DCs available, the chances of someone in his group going into deco is reduced regardless of the computer each diver is using. It has gotten to the point that when on a dive trip I also look to see what DC the DM is wearing. Not that it is all that important to me. just curiosity. And I have found that usually, it's a Suunto. Now, granted, I haven't dived all over the world like some folks have, but this has been my observation in the places I have been.

So next time a smartass says something about your Suunto, check to see what the DM is wearing. It may not matter what smartass is wearing if the DM has a Zoop.