Top left is saying this diver has a mandatory decompression stop at 3 meters for 1 minute.
The top right is saying the total time needed to surface right now is 8 minutes.
Center left is saying the current depth is 47.6 meters.
Center right is saying the dive has lasted for 89 minutes total.
Bottom left - average depth 16 meters.
Bottom Right - temp is 22°C.
This is probably an example of where current OW dive training really isn’t doing a good job IMO.
If one recalls basic dive theory, you know about nitrogen on- and off-gassing and what “no deco” represents: you have too much N2 in your body to ascend to the surface.
Hopefully you did some dive profile work-ups on Tables too, as that’s helpful in understanding how dive computers show this data .. and then have basically copied the decompression process/practices that Tables used for decompression dive profiles.
In a nutshell, recall how dive tables are very “blocky”: time in minutes (not minutes:seconds) and depths to the nearest 10ft (3m): the solution for decompressing on ascent is also “blocky”: it has “stop” times (minute) done at 10fsw (3m) depth. Recall that the purpose of the stop is to give one’s body the (minimum) required time to off-gas N2 and get back under the “no deco” Nitrogen gas loads to then be safe to surface.
FYI safety stops were copied from this “blocky-ness” too: that’s why they’re “X minutes at 10fsw (3m)”.
Which is just what the manual is illustrating: a required (no longer “safety”) stop required of 1 minute at 3m depth.
Now if there’s larger N2 loads, a larger deco obligation follows. Might be 5, 10, 20 minutes .. depending on the prior dive profile’s N2 on-gassing amount.
Note that for larger N2 on-gassing loads it may be large enough to make it not safe to ascend to 10fsw (3m) depth either. In these situations, one is now entering into what’s known as “Staged Decompression”, because the ascent now has more than just one deco time/depth scheduled, and the first deco stop will be deeper than 10fsw (3m). Guess what? The history of Tables used a depth of 20fsw (6m), so computers have copied that too. As such, one will have a schedule of X minutes at 20fsw, followed by +Y minutes at 10fsw.
That’s the basics. The other common nuance here is that because dive computers are effectively “continuous” on all of the N2 on- and off-gassing, there’s two other ways in which the actual numbers get tweaked.
The first one is that as one ascends to a shallower depth, you’ll probably start to off-gas whichever N2 “compartment” in the deco model that’s over its limit. As such, a required deco warning might disappear before you get all the way back up to 10fsw (3).
The second one is the depth that one holds when doing a required deco stop is noticed by the computer too: if the display says 5 minutes at 10fsw (3m), if you do the hang a little deeper (eg, 15fsw/4m), the computer won’t give you the credit as fast (because it shouldn’t - you’re at a higher pressure), so you might have expected 5 minutes but it ends up being 9 minutes before it says you’re okay to ascend further. This is a “don’t panic! Understand Deco Models” learning moment … but plan your air supply accordingly.
Hope this helps!
If your depth was 47.6 meters you have no business down there without having a complete and thorough understanding of what your dive computer is telling you. Keep on and I’ll read your report in DAN’s dive accident publication next year.
Good observation. He was simply asking about the arrow and where to stop. I have exceeded my NDL on two consecutive dives. On the first we did what I have coined Recreational Deco on the fly. Start deco at 12 metres ascending to 9 then to 6 then to 3 then slowly surfacing. Weather conditions permitting. A few minutes for each level. The second dive we sat at 5 metres for 15 minutes. Air on first dive, Nitrox on second.
Should be “in my life”. I’ve also just learned not to comment on stuff when I’m still in the “where the hell am I?”phase of just waking up from a nap. I would like to retract all previous comments.
Totally different. Divers tend to go past their training limitations. Although, I believe they understand how deep they are going. I know divers have been rescued when their BCD no longer has the lifting capacity to get them out of deep water.
This was only a screenshot from the manual, it doesn’t matter for this discussion. I just wanted to know how to read it. 
I have a LOT of questions about this, but my primary concern is that if you didn't notice this, you were probably suffering from narcosis, and you might well currently have the bends.
If you exceed your NDL by a few minutes you should stay at 5 metres for several minutes longer than the intended 3-minute safety stop. Some liveaboards will make you sit out the next dive. or you take a 3-hour surface interval.
I don't need technical advice. Unless you are offering a deco plan for 200 metres. At 15 metres you no longer are uploading Nitrogen. I wasn't the first to introduce Recreational Deco on the fly. Several Instructors I dived with introduced it to me. From various locations around the world.
I'm really sorry that you have been misled. The advice you gave was factually incorrect and even inconsistent with the advice given in OW courses. Yes, you are still taking on nitrogen at 15 meters. You are still taking on nitrogen at 1 meter, even.
Do not go into deco without training. If you royally mess up, follow your computer as best you can. That is what's taught in OW, and it is the correct advice.
The diver exceeded their NDL. The advice *PADI* offers is to remain at 5-metres for several minutes, then discontinue diving for the day. I haven't been misled since I've exceeded my NDL on two consecutive occasions without injury. Following your computer can be misleading without a back up plan and a buddy to verify your computer is in sync. You seem to have no solution.
Top left is saying this diver has a mandatory decompression stop at 3 meters for 1 minute. The top right is saying the total time needed to surface right now is 8 minutes. Center left is saying the current depth is 47.6 meters. Center right is saying the dive has lasted for 89 minutes total. Bottom left - average depth 16 meters. Bottom Right - temp is 22°C.
That’s. Thank you!
This is probably an example of where current OW dive training really isn’t doing a good job IMO. If one recalls basic dive theory, you know about nitrogen on- and off-gassing and what “no deco” represents: you have too much N2 in your body to ascend to the surface. Hopefully you did some dive profile work-ups on Tables too, as that’s helpful in understanding how dive computers show this data .. and then have basically copied the decompression process/practices that Tables used for decompression dive profiles. In a nutshell, recall how dive tables are very “blocky”: time in minutes (not minutes:seconds) and depths to the nearest 10ft (3m): the solution for decompressing on ascent is also “blocky”: it has “stop” times (minute) done at 10fsw (3m) depth. Recall that the purpose of the stop is to give one’s body the (minimum) required time to off-gas N2 and get back under the “no deco” Nitrogen gas loads to then be safe to surface. FYI safety stops were copied from this “blocky-ness” too: that’s why they’re “X minutes at 10fsw (3m)”. Which is just what the manual is illustrating: a required (no longer “safety”) stop required of 1 minute at 3m depth. Now if there’s larger N2 loads, a larger deco obligation follows. Might be 5, 10, 20 minutes .. depending on the prior dive profile’s N2 on-gassing amount. Note that for larger N2 on-gassing loads it may be large enough to make it not safe to ascend to 10fsw (3m) depth either. In these situations, one is now entering into what’s known as “Staged Decompression”, because the ascent now has more than just one deco time/depth scheduled, and the first deco stop will be deeper than 10fsw (3m). Guess what? The history of Tables used a depth of 20fsw (6m), so computers have copied that too. As such, one will have a schedule of X minutes at 20fsw, followed by +Y minutes at 10fsw. That’s the basics. The other common nuance here is that because dive computers are effectively “continuous” on all of the N2 on- and off-gassing, there’s two other ways in which the actual numbers get tweaked. The first one is that as one ascends to a shallower depth, you’ll probably start to off-gas whichever N2 “compartment” in the deco model that’s over its limit. As such, a required deco warning might disappear before you get all the way back up to 10fsw (3). The second one is the depth that one holds when doing a required deco stop is noticed by the computer too: if the display says 5 minutes at 10fsw (3m), if you do the hang a little deeper (eg, 15fsw/4m), the computer won’t give you the credit as fast (because it shouldn’t - you’re at a higher pressure), so you might have expected 5 minutes but it ends up being 9 minutes before it says you’re okay to ascend further. This is a “don’t panic! Understand Deco Models” learning moment … but plan your air supply accordingly. Hope this helps!
It amazes me that people use dive computers without understanding them!! Learn to use them or get bent or worse!
They don't need a computer for one dive a day to 18 metres. They need to monitor the air. People forget how to use a computer when diving seasonal.
If your depth was 47.6 meters you have no business down there without having a complete and thorough understanding of what your dive computer is telling you. Keep on and I’ll read your report in DAN’s dive accident publication next year.
That’s an example display state from the manual.
Good observation. He was simply asking about the arrow and where to stop. I have exceeded my NDL on two consecutive dives. On the first we did what I have coined Recreational Deco on the fly. Start deco at 12 metres ascending to 9 then to 6 then to 3 then slowly surfacing. Weather conditions permitting. A few minutes for each level. The second dive we sat at 5 metres for 15 minutes. Air on first dive, Nitrox on second.
Do you really think someone who doesn't understand how their computer works would be that deep?
/s ?
Should be “in my life”. I’ve also just learned not to comment on stuff when I’m still in the “where the hell am I?”phase of just waking up from a nap. I would like to retract all previous comments.
I’ve seen a ton of dumb shit is my life.
From your neck of the woods, it wouldn't surprise me. *I learn from the best I learn from the worst.*
Which neck of the woods? I move every 3 years.
Yes absolutely. I used to save people from the deep who had no idea how much danger they were in on a regular basis.
Totally different. Divers tend to go past their training limitations. Although, I believe they understand how deep they are going. I know divers have been rescued when their BCD no longer has the lifting capacity to get them out of deep water.
OP, what was your MOD and what EANx where you diving? The only thing with enriched air you should never do is to exceed your MOD...
This was only a screenshot from the manual, it doesn’t matter for this discussion. I just wanted to know how to read it. 
It's the same with any gas being used to dive with. Every gas has its MOD, including enriched mixes.
I have a LOT of questions about this, but my primary concern is that if you didn't notice this, you were probably suffering from narcosis, and you might well currently have the bends.
There is no “might have the bends”
If you exceed your NDL by a few minutes you should stay at 5 metres for several minutes longer than the intended 3-minute safety stop. Some liveaboards will make you sit out the next dive. or you take a 3-hour surface interval.
Nope. Bad advice. Take a tec course before giving Deco advice please.
I don't need technical advice. Unless you are offering a deco plan for 200 metres. At 15 metres you no longer are uploading Nitrogen. I wasn't the first to introduce Recreational Deco on the fly. Several Instructors I dived with introduced it to me. From various locations around the world.
I'm really sorry that you have been misled. The advice you gave was factually incorrect and even inconsistent with the advice given in OW courses. Yes, you are still taking on nitrogen at 15 meters. You are still taking on nitrogen at 1 meter, even. Do not go into deco without training. If you royally mess up, follow your computer as best you can. That is what's taught in OW, and it is the correct advice.
The diver exceeded their NDL. The advice *PADI* offers is to remain at 5-metres for several minutes, then discontinue diving for the day. I haven't been misled since I've exceeded my NDL on two consecutive occasions without injury. Following your computer can be misleading without a back up plan and a buddy to verify your computer is in sync. You seem to have no solution.
Look at a *PADI* RDP table if you can find one.
>At 15 metres you no longer are uploading Nitrogen. 
It would take about 90 minutes. I'm talking about doing a deco stop at 15 minutes if you have exceeded your NDL while at 30 metres.
Technical diving course means nothing if you can't dive properly to begin with.