Aeris computer deco violations

[ianr33]

ian,

It does all make me worry a bit since my tables show 20 min at 100' as NDL. You doing 10 minutes of deco as I cruise on past you would make me a little nervous when I ask you about it on the boat ride back to shore.

Another thing to bear in mind is that the 20 minutes at 100' NDL from tables includes the descent time .That would be around 2 minutes,so what you really have is 18 minutes at 100 feet,whereas (I presume anyway) the computer is allowing you 19 minutes at 100 feet,a little longer than the tables.

The tables have some conservatism built in as they use a maximum depth.The computer does not. Consider a dive where the bottom section varies between 100 feet and,say 80 feet (with an average of 90 feet) Going by tables you need to ascend 20 minutes into the dive.The computer will be nudging the NDL at around 26 minutes (24 minutes NDL @ 90' +2 minutes for descent time. Thats a significant difference.

The easy way to stay safe is to start ascending if the computer goes into the yellow at all.As you gain experience dive it into the yellow but include a LONG safety stop.Start slow and get to know your computer and how it behaves. Get a feel for how long it takes to go from nudging the NDL to dropping into the green.That will vary with depth/profile but is probably at least 10 minutes at 15 feet.

I much prefer a liberal computer where it is easy to set your own level of conservatism rather than,say,a Suunto that will lock you out at the drop of a hat.

 

[WallDiver77]

I have found this thread very interesting!

I dive an Aeris 500 AI... which would now make it one of Aeris's older versions of it's AI type computers.

I have dove this computer to depths 190'+ with no problems. These have been, of course, deco dives. I've always made, at the least, one minute to two minute stops at half the max depth of my dives. Then we skidaddle right on up to the SECOND half depth stop. AT this point a few, important, factors must be considered to determine what the remainder of the dive looks like. Remaining air time, what stops the computer is telling me to make, and how long at these stops.

It has been my experience with my Aeris that the computer really starts "crediting" me with more dottle-around-the-top-of-reef time with this type of profile. (I'm obviously NOT diving this type of profile with an AL80.)

With this profile, I can't remember my Aeris ever telling me to make a mandatory stop below 20 feet. Just the same, I've been making them. I have, rarely, exited the water with one remaining Yellow bar.

Point: I trust what my Aeris is telling me.

 

[nineeightysix]

FWIW,

I checked my Atmos AI manual and it states the computer will calculate deco stops as deep as 60', but also clearly states that unless you dive a square profile it will give credit for all time above the max depth. This of course makes sense, and might help explain why the deep stops seem hard to come by...

I have the latest hardware/software combination if it makes a difference.

 

[Doug Krause]

OK - 986 asked me to come by. I've read through the posts, a lot of great questions and some good answers. I'm not sure where to begin here, so let's start over for my sake - I'll take a stab at any new questions or previous posts that need clarification.

Doug

 

[boat sju]

Doug,

Thanks for dropping by. Could you give me an idea what times would put me just into the "yellow" on my XR-1, for say 70-120 ft (first dive of course)? I haven't dove with it yet - it only has one yellow bar before deco, right?

Thanks,
Steve

 

[nineeightysix]

Doug,

Thanks for stopping by. Can you comment on some of the points made in this thread:

- Aeris' view towards the algorithm used versus others (RGBM specifically)?

- All things being equal, what does the yellow zone indicate -- can you get easily get bent coming up in the yellow zone? (I realize this is a very broad question)

- Under what conditions will an Aeris DC require deep stops? Most here have seen a 20ft ceiling as the lowest.


Cheers

 

[Doug Krause]

Doug,

Thanks for dropping by. Could you give me an idea what times would put me just into the "yellow" on my XR-1, for say 70-120 ft (first dive of course)? I haven't dove with it yet - it only has one yellow bar before deco, right?

Thanks,
Steve

- 5 feet per second descent rate
- Depth = 100 feet
- FO2 = AIR

Yellow pixel active at 15 minutes elapsed dive time.

The XR-1 has a total of 5 tissue loading bar graph segments - 3 GREEN, 1 YELLOW and 1 RED.

 

[boat sju]

So the XR-1 goes to yellow at 15 minutes which actually corresponds to the second yellow bar of the Elite. That's good to know. I'll stay out of the yellow.

Thanks Doug.

 

[Timeliner]

So the XR-1 goes to yellow at 15 minutes which actually corresponds to the second yellow bar of the Elite. That's good to know. I'll stay out of the yellow.

Thanks Doug.

Yellow is such a pretty color though. I like red too. Green is OK I guess. Remember... Your talking about a graph on your dive computer not a leasure suit. I have a Atmos 2
I'll tell you a little secret ...........
So far in my life I have survived both the Yellow Suit and the Yellow & Red Graphs many times. The drive home is the dangerous part !

 

[Scuba-Jay]

interesting thread. I just picked up my new Aeris and sat down to calculate a plan for the same scenario. Ill post them if i can find them!! (=