Atomic Aquatics Cobalt Dive Computer

[erik44_2]

Ron

have question on the dive planner on the cobalt i notice last night after i was using it in the simulation mode and the dive planer that the NDL limits are very different from padi dive planner it seems that the cobalt is more Conservative than padi for example on the cobalt at 60 ft the NDL is 51 min and on the padi dive planner the NDL is 55 minutes

---------- Post added at 07:38 AM ---------- Previous post was at 07:30 AM ----------

Ron

I have question on the cobalt dive planner i notice last night while using the stimulation dive planner mode that the NDL on the cobalt is 51 min and on my PADI dive planner the NDL is 55 minutes why is the cobalt planner is more Conservative than PADI so if was diving at 60ft and go with the cobalt dive planner and stayed at 55 min knowing that the PADI planner i can have ndl of 55 min if this said wouldnt i be in violation on the cobalt computer but knowing that im safe at 55 min using the padi dive planner

 

[RonR]

Ron

have question on the dive planner on the cobalt i notice last night after i was using it in the simulation mode and the dive planer that the NDL limits are very different from padi dive planner it seems that the cobalt is more Conservative than padi for example on the cobalt at 60 ft the NDL is 51 min and on the padi dive planner the NDL is 55 minutes... <snip>

There are going to be some variations in no deco times between all dive computers and planners. The variations, measured in minutes of no deco time, will always be largest at shallow depths, as they are percentage variations. The conservatism level you set for the Cobalt will affect the no stop times, as will the age you enter for yourself.


What was your altitude when you were looking at the Cobalt? It bases the no stop times in the table on current atmospheric pressure, which you can see in the System info (sea level being ± 1000 mbar). Just checking one here at sea level I get 53 minutes at 60 feet for a 62 year old at standard risk level. PADI tables, of course, are just assuming sea level.


But mainly, at 60 feet, you are not far below a depth with virtually unlimited no deco time. If you look at a comparison for a greater depth, you will see values converge. If you can visualize the no-stop times as defined by a curve crossing a line, at shallow depths, the curve is quite flat, nearly parallel to the line it is crossing. A tiny percentage variation in the slope will result in many minutes variation in the crossover to deco point, but the crossover is barely there. I quote Eric Baker's observation that all decompression algorithms are "an attempt to draw a bright, sharp line through a fuzzy gray area". Both the Cobalt and the PADI table have to treat this as a binary choice, but really it isn't- we live in an analog world. So it's possible that at 55 minutes you would be in deco- technically- on the Cobalt, and it might require a one minute stop at 15-20 feet, but it is barely into deco, and doesn't mean the PADI tables are wrong, and it's not a violation unless you don't do the stop. The actual difference between the two is probably tiny.

Ron

 

[erik44_2]

Ron


im at 979 mbar in the system info and I do understand that many of the dive tables are different and i do understand everyone is different and the dive table are base line for safe diving i know that us navy table give you more Ndl time then all the dive tables and i notice on cobalt at 140ft that the ndl is 7 min and the padi dive table is 8 with said there 1 minute differance but will i dive at depth no i wont never but there is 4 minute difference at 60ft i just curious in the difference between cobalt and padi aslo i know that on my pro plus 2.0 had longer NDl I dont solely rely on my dive computer i still carry my dive planers with and corresponded to the difference between computer and divetables and most of the time when i dive im doing multi level dive I guess im just trying to learn the in and outs of my computer or i could say have lot of question because i have curious mind and i really dont dive in my area not much to see on lake superior water is cold and not much to look at lol

 

[entropy]

Just got back from Indonesia with the Cobalt. My cobra died after 400 dives. Big switch, the Cobalt is easier to use. Very sweet.

Questions:
1. On the dive log summary page it shows CNS and OTU for each dive. There is no real explanation in the user PDF. Where can I find more details?
2. Other than thoroughly rinsing in water - not salt water - and keeping in a dry place for a few months before diving again, any special to do?
3. Do I rinse with the connector cap on or off?


Thanks, Lydia

 

[RonR]

Just got back from Indonesia with the Cobalt. My cobra died after 400 dives. Big switch, the Cobalt is easier to use. Very sweet.

Questions:
1. On the dive log summary page it shows CNS and OTU for each dive. There is no real explanation in the user PDF. Where can I find more details?
2. Other than thoroughly rinsing in water - not salt water - and keeping in a dry place for a few months before diving again, any special to do?
3. Do I rinse with the connector cap on or off?


Thanks, Lydia

Lydia, Glad you like the Cobalt.


On #1, this is a short answer to a complex question:


CNS and OTU both have to do with different forms of oxygen toxicity. For open circuit EAN diving, CNS is the one that you need to be concerned with, and CNS limits will always be the controlling factor. O2 builds up in the tissues, and prolonged exposure, as you might get with multiple EAN dives or decompressing on pure O2, can push the diver into risk territory. Keeping your CNS exposure within limits helps avoid acute oxygen toxicity, as will keeping your PO2 within safe limits. The Cobalt will alert in the dive screen if CNS 80% is exceeded. What you need to do then is go up and breathe some AIR 21% for a while to let some of the O2 off gas.


OTU's are not much of an issue until you get into serious technical or saturation diving territory, but they might be of value if a chamber treatment is needed, so the value is stored and displayed for the dives.


There is plenty of information about this in EAN classes, and on the web. An article by the late Bill Hamilton is here: http://www.oceanwreckdivers.com/images/tolerating_exposure_to_high_oxygen_levels.PDF and a DAN workshop on Nitrox is here: http://www.diversalertnetwork.org/files/DANnitrox_web.pdf


One of the best articles I've found for general use is Oxygen Toxcicity Calculations, By EriK Baker, many links online, one here: http://www1.maths.leeds.ac.uk/~read/scuba/baker3.pdf


#2- Nothing special- rinse well, store dry, in possible with the battery charges so it doesn't go flat in storage. A fully charged battery should be good for nearly six months of standby. There is no harm in charging from any state, the batteries don't have a "memory" problem. Keep the USB pins clean, some have had connection troubles if they get dirty or oily.


#3- It doesn't matter, water getting inside the HP opening won't hurt anything, so if salt water got in I'd rinse it out as well.


Ron

 

[MO50]

Whenever I plan a deco dive in the dive planner, after its saved it shows the dive was 224 min long. This happens no matter how long I had the dive at when I saved it. I am running the latest software, but this problem also happened on the previous version.

 

[RonR]

Whenever I plan a deco dive in the dive planner, after its saved it shows the dive was 224 min long. This happens no matter how long I had the dive at when I saved it. I am running the latest software, but this problem also happened on the previous version.

This is a bug that popped up in the last release- and was in one prior release as well. The time is correct in the dive profile, but not in the list display of saved SIM dives. If you PM me with an email I'll send you a new version that fixes this

Ron

 

[MO50]

This is a bug that popped up in the last release- and was in one prior release as well. The time is correct in the dive profile, but not in the list display of saved SIM dives. If you PM me with an email I'll send you a new version that fixes this

Ron

PM sent

 

[DColumbus]

Hi all,

I have been following this thread for a long time, while deciding to buy the Cobalt. I have a question, I guess for RonR. I will be getting a Cobalt from my local dive shop this week, and I want to know what is the latest software version so I can check that I have the latest from the shop. Then I'll wait for the next updates from Atomic.......waaaay down the calendar, around the week of March 19... Any input from any experienced users would also be appreciated.

Dan

 

[RonR]

Hi all,

I have been following this thread for a long time, while deciding to buy the Cobalt. I have a question, I guess for RonR. I will be getting a Cobalt from my local dive shop this week, and I want to know what is the latest software version so I can check that I have the latest from the shop. Then I'll wait for the next updates from Atomic.......waaaay down the calendar, around the week of March 19... Any input from any experienced users would also be appreciated.

Dan

A new Cobalt might display either 1.13 or 1.17 installed depending on when it shipped from Atomic, there is very little difference between these versions. 1.17 improved the scaling in the Dive Log Profile screen, and added an alternating time of day display in the dive screen. If you have 1.13 I would not bother updating until 1.18 of more comes out.

To address the larger question, some people are obviously concerned that there are different firmware versions out there, and are assuming that because Atomic releases a new firmware update, it's because there is some problem with the older versions- that is not the case. Version 1.11 (released in May of 2011) was the last update that included a fix for what we saw as a significant bug, and that was a very uncommon one- if a diver had selected a 90 second data storage interval in an early firmware version (not possible in more recent versions), then updated, accessing that dive profile in the log could cause the Cobalt to temporarily lock up. Version 1.12 changed the tones in the sounder to ones most people felt were easier to hear, which wasn't a bug fix but did help improve the product in the view of many.

Since then each update has included some bug fixes, but these have been for minor issues where the display didn't show what we wanted it to in some very specific situations- like issues around gas switching when only one alternate mix is defined, the leap year date display, displaying gas consumption predictions in the Simulator, or spelling errors in German. (And many thanks to those of you who have spotted these issues and let us know about them, you are helping us make the Cobalt a better product.) None of these issues have been things that affected the basic functioning of the Cobalt. Most of the reason for version updates has been to add or enhance features, or to improve the display on non-English versions.

On the Update page, I've tried to keep a version history accurate so you can see what is being changed in each new update. We want to keep updating the Firmware to enhance and improve the product, and we want everyone to keep up as much as is reasonable with the latest versions, but if there is a problem that has to do with the functioning of the Cobalt, we will let you know.

Atomic should have the new Windows software up soon- this week I hope- with a much improved driver. Too many people had problems with this software on Windows systems when the last firmware update was released at the end of February. That is the reason the software download page has been inactive the last few weeks. I'll try to get more information tomorrow.

Ron