Remaining Air Time calculation on Suunto Vyper Novo

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Evaldas

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Trying to figure out the Remaining Air Time calculation on air integrated Suunto Vyper Novo. Was reading the manual and could not figure out if Remaining Air Time
calculation only takes into account the current depth and air consumption plus the 500 psi safety reserve, or does it also take into account the air required for the ascent based on the current depth, including the required safety stops, etc.
Also could not figure out how to plan the Air Time for the dive based on the planned depth and recorded air consumption from the previous dives either using the dive computer itself or the Suunto D5. Is there such functionality available?
 

GreggS

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It takes current depth and computes your air time remaining to 500 psi or whatever pressure you have set as your end of dive pressure. If you haven't noticed yet, as you ascend from depth, your remaining air time will increase.
 

inquisit

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I don't use that computer, but ascent is typically ignored. You may be able to increase the reserve value it uses to include the air required for ascent & safety stop. From 60 ft with 3 minute stop, multiply your SAC rate (in PSI) by about 8 for that additional amount. At 90 ft, 11.5 is the multiplier. Get your SAC rate (Surface Air Consumption) from your computer for a prior dive. Google that for the math behind those multipliers.
 

inquisit

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Most computers don't have air planning functionality. After you read up on SAC rate, you can do the calculations yourself. The short answer for the multiplier is
Time * (Depth_meters+10)/10 or
Time * (Depth_ft+33)/33.

For example, for 30 minutes at 60 ft, multiply your consumption (SAC) by
30 * (60+33) / 33 = 84.5.
If your SAC is about 20 psi/min (a good rate with an AL80 tank), you'll burn about 1700 psi for that bottom portion.

For a multilevel dive, do each level separately and add everything up. Alternatively, the total time at the max depth is a conservative estimate and easier.
 

inquisit

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I think it's great you're looking to plan your air. Along those lines, consider what that 500 PSI reserve is for -- to get your buddy up during an air share. Recall that multiplier for 60 ft ascent was 8 (with safety stop). If buddy's rate is the same as yours but in the stress of the moment doubles and yours doubles, that's 24x the normal rate. (Not 32x since you were already planning on a normal accent without using the reserve.) If your consumption (SAC) is normally 20 psi/min, you'll just barely make it.

If you or they have worse consumption rates or ESPECIALLY if you're deeper, that measly 500 PSI won't cut it.
 

Evaldas

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Thank you so much for the explanation. This is why their calculation of remaining air time based on 500 psi reserve did not make sense to me. I know it also has additional warning alarm set at 700 psi that you can manually increase if required, but obviously for the planning purposes it does not really do any good as you have to figure out these limits manually anyway. I wonder if their DM5 software has any such planning functionality.
 

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Thank you so much for the explanation. This is why their calculation of remaining air time based on 500 psi reserve did not make sense to me. I know it also has additional warning alarm set at 700 psi that you can manually increase if required, but obviously for the planning purposes it does not really do any good as you have to figure out these limits manually anyway. I wonder if their DM5 software has any such planning functionality.
Absolutely correct. I used the Vyper Novo for 4 years. Can you use it to plan dive time on future dives? Sure, I suppose you can. I no longer use the Vyper Novo, having switched to an Oceanic OCi. But it works the same way in regards to dive time remaining. And before the Novo, I used the Vyper Air. Again, it worked the same way. I've used air integrated computers long enough that I can quickly figure out in my head approximately how long my air will last if I know how deep I'll be going. Of course, every dive is different with different underwater terrain, different levels of stress, strong or weak currents, and other variances that will cause your air consumption to change. That's why the dive time remaining is so important to the dive you are using it on.

And glad to help. Have fun out there and be safe.
 

GreggS

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Thank you so much. I am just considering purchasing it and trying to figure out if the AI is really worth that extra money.
Okay, gotcha. I love AI, especially when using a wrist computer. All your dive information is right there in an easy to see location . The Vyper Novo is a nice computer. Like I said, I used different Suuntos for years. But one thing that you'll read here on Scubaboard, is that Suuntos, especially the lower recreational DCs like the Vypers and Zoops, run proprietary algorithms which are the most conservative on the market. It just depends on what type of diving you plan on doing. You might also want to take a look at the Oceanic computers, which run a dual algorithm (you can choose which one you want to run), or the Shearwater computers which I think has an adjustable algorithm. (never used a Shearwater myself, so I could be wrong about that, but have read wonderful things about them.) Also, the Suunto's transmitter is proprietary and can only be used with certain Suuntos. And, if you buy the Vyper Novo and later decide to upgrade to one of their upper computers like the Eon Core, guess what. You'll have to buy another transmitter as those use a different one that is also proprietary. The Oceanic and Shearwater computers use the same transmitter and will also work with Sherwood computers and a few other brands.

Oh, and BTW. If you do go with the Suunto, I highly recommend dumping DM5 and going to some other diving software such as Subsurface (free) or any number of other free or commercially available dive log software. DM5 is atrociously and notoriously bad. When I was using it early on with my Vyper Air, it got to where it would not download my dives. It would say it was downloading them but they never showed up in the logbook.

I switched to Subsurface years ago and have been very happy with it. Like I said, it is free, has versions for PC, Mac, and Linux, and gives you quite a bit more information about your dives than DM5 does. It has a mobile app for Android and iPhone and you can download your dives direct to your mobile device and then open them on the desktop version or vice-versa.
 
https://www.shearwater.com/products/teric/

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