What is my computer telling me - Air time remaining

[Yellowdog]

I am looking at the data from a recent dive in Cozumel and I am not exactly sure what the air time remaining function is telling me. I have a Oceanic Pro Plus 3 and I am viewing the data on the Oceanic Dive Log program from one dive on a week long dive trip. At 40 minutes into the dive the data shows:

elapsed time 00:40
depth 57ft
TLBG 4
pressure reading 735psi
Air time remaining 0:06
Dive time remaining 0:13
NDC 0:17
max 82ft

I have already started my ascent at this point in the dive and I reach the surface 7 minutes later with 510psi, after a 3 minute safety stop at 15ft. My question is what is the Air Time Remaining information in this example telling me. Is it that I need to start my ascent from this depth in 6 minutes or that I will run out of in 0:06 minutes if I stay at this depth or something else?

 

[Redshift]

I'd say the manual is the best place to look for that information.
But I guess it makes sense that the computer is telling you how much gas you have at that depth.

 

[rhwestfall]

6 minutes of air at this depth and consumption rate (wrong)
13 minutes inclusive of recommended stops, (a.k.a.: TTS)
17 minutes remaining w/o DECO (ceiling)

none are related to each other, and you need to monitor each to decide the limiting element...

 

[eelnoraa]

elapsed time 00:40
depth 57ft
TLBG 4
pressure reading 735psi
Air time remaining 0:06
Dive time remaining 0:13
NDC 0:17
max 82ft

I have used Oceanic AI for a long time. Here is what they mean:
ATR = 0:06 means based on current consumption, you should start your ascent in 6 minutes. When you reach surface, you will have minimum reserved air in your tank. This min reserved air is another parameter you can set in the computer.

DTR = 0:13 means if you follow the computer, you will be on the surface in 13 minutes. This is you start ascent in 6 minutes, the ascent will take 7 minutes total (including all stops)

NDC = 0:17 means based on the current dive profile, you NDL time is 17 minutes.

 

[Mr Carcharodon]

Air time remaining is likely the time you have left at the current depth until you hit a pressure reserve number. That is typically 500 psig. Why 500 psi, oh hell we don't know, only that it is what has always been used. This is a fairly useless metric if you are already ascending, as you were. It could be useful if you are planning on hanging out at that depth for awhile. The people who program the dive computers do not have much insight into your dive planning (how could they?) and that limits the value of their advise. Check what pressure air time remaining goes to zero at and you will know for sure what it is doing.

Going below 500 psi seems pretty reasonable if you are shallow, say 15 or 20 fsw, and know conditions permit an uneventful exit. Poking at the limits your dive computer gives you is a reasonable thing to do.

 

[Dnaber]

Yellowdog, have you contacted Oceanic about the activation code for the free online training offered by eDiving. That training may help you understand and use your computer correctly.

 

[Yellowdog]

I'd say the manual is the best place to look for that information.
But I guess it makes sense that the computer is telling you how much gas you have at that depth.

You would think but unfortunately the manual is not very helpful

 

[mfalco]

I would assume it is the same as on the Pro Plus 2 model. On that it is time remaining until you reach the end pressure alarm set point.

 

[Texasguy]

I have Oceanic VT4. When I was at 100 feet, it would tell me I have like 9mins left. Then I start my assent. By the time I am in 20 feet, the comp would show I have like 40 mins left.

Probably it is unnerving to see 9mins of air left on your computer when you are in for 10 min assent. I know I had my own doubts.

 

[DiveNav]

Yellowdog, have you contacted Oceanic about the activation code for the free online training offered by eDiving.

You mean the Pro Plus 3 class on Dive Computer Training right?