cochran commader ?'s

[Jay Roy]

Hi there

I have recently switched computers from a Suunnto Gekko to a Cochran Commander and I was wondering if anyone could answer a question for me...I'm used to my Gekko showing a safety stop, my Cochran doesnt show a stop. I'm wondering if that is because I have the conservitism set at 00% or it's never supposed to show a safety stop, or is the thing just not working properly....Thanks

 

[cameron]

when you get to the 20 mark look at the time and add 3-5 min. The commander doesnt do this for you

 

[Vie]

Cochran computers don’t do the “countdown” thing. IMHO, I would set your Commander’s conservatism to at least 25% (unless you are using it as a backup/bottom timer) or plan your dives using your dive table—the Commander is a very “aggressive” computer.

 

[JS1scuba]

Hi there

I have recently switched computers from a Suunnto Gekko to a Cochran Commander and I was wondering if anyone could answer a question for me...I'm used to my Gekko showing a safety stop, my Cochran doesnt show a stop. I'm wondering if that is because I have the conservitism set at 00% or it's never supposed to show a safety stop, or is the thing just not working properly....Thanks

The Cochran Commander (or EMC or Gemini series) will not show you a required safety stop when you reach 20 fsw. You will need to do that on your own. A saftey stop by definition is an "optional" stop when doing no-stop dives. The Suunto makes it a requirement even though it is in reality an option.

What you may want to do with the Cochran to make it a little more conservative is to set the Con factor to 8 or 10 -- that will shorten the planned square no-stop times and may insert a ceiling requiring a stop if you want something more conservative.

Regards,

 

[padiscubapro]

Cochran computers don’t do the “countdown” thing. IMHO, I would set your Commander’s conservatism to at least 25% (unless you are using it as a backup/bottom timer) or plan your dives using your dive table—the Commander is a very “aggressive” computer.

how one views a computer's conservatism is really a personal opinion..

On the profiles I routinely do, I find the emc-20h at 0 conservatism is overly conservative. A person's physical condition has to be taken into account.


The older commanders on 0 conservatism gave profiles close to an unmodified buhlman, allowing the diver to truely tailor the profile.. The cochrans base conservatism has varied over time.. The current emc-16 and emc20-h with deep stops will produce a much safer profile than most other computers with similiar settings..

I know how my body reacts to various profiles, and find with the current version it is projecting more deco than I have to.. Joel's suggestion for setting the conservatism to an 8-10 is a good recommendation for recreational divers and will force a "deco" stop slightly earlier than the no deco limits..

I was lucky enough to dive several versions of the emc-20h as they were being developed and able to see how the profiles changed.. The baseline conservatism of the current version is still more conservative than an unmodified buhlman profile.

To put things into context, I do profiles that routinely require 2-3 hours of deco (and even more), with 0 conservatism, the cochran typically has 20-30 minutes more deco (when I started trying the emc-20h it was almost double this) than my Explorer and HammerHead.

 

[Vie]

The older commanders on 0 conservatism gave profiles close to an unmodified buhlman, allowing the diver to truely tailor the profile.. The cochrans base conservatism has varied over time.. The current emc-16 and emc20-h with deep stops will produce a much safer profile than most other computers with similiar settings...

Hi padiscubapro,

I bought one of the last Commander before the switch to the EMC-16 model. What are the differences between the Commander and the EMC-16 apart from the name change? I know that the EMC-16 can use two different types of batteries but have not been able to find out much else.

 

[JS1scuba]

how one views a computer's conservatism is really a personal opinion..

On the profiles I routinely do, I find the emc-20h at 0 conservatism is overly conservative. A person's physical condition has to be taken into account.


The older commanders on 0 conservatism gave profiles close to an unmodified buhlman, allowing the diver to truely tailor the profile.. The cochrans base conservatism has varied over time.. The current emc-16 and emc20-h with deep stops will produce a much safer profile than most other computers with similiar settings..

I know how my body reacts to various profiles, and find with the current version it is projecting more deco than I have to.. Joel's suggestion for setting the conservatism to an 8-10 is a good recommendation for recreational divers and will force a "deco" stop slightly earlier than the no deco limits..

I was lucky enough to dive several versions of the emc-20h as they were being developed and able to see how the profiles changed.. The baseline conservatism of the current version is still more conservative than an unmodified buhlman profile.

To put things into context, I do profiles that routinely require 2-3 hours of deco (and even more), with 0 conservatism, the cochran typically has 20-30 minutes more deco (when I started trying the emc-20h it was almost double this) than my Explorer and HammerHead.

Joe, I base all my comparisons on Hamilton Research DCAP algorithm. The early versions of the EMC20 would scream past those with at least 50% less deco. Now the EMC20 set at 8 matches up. I do know that in CCR mode the EMC20 was slower than the Explorer but then the explorer is way too fast (imho) for oc diving.

If you would like me to cut you a CCR profile on HRLs DCAP ping me an email off line.

Cheers
jds

 

[padiscubapro]

Joe, I base all my comparisons on Hamilton Research DCAP algorithm. The early versions of the EMC20 would scream past those with at least 50% less deco. Now the EMC20 set at 8 matches up. I do know that in CCR mode the EMC20 was slower than the Explorer but then the explorer is way too fast (imho) for oc diving.

If you would like me to cut you a CCR profile on HRLs DCAP ping me an email off line.

Cheers
jds

I never liked DCAP too slow (at least profiles I have seen - and hangs I have seen by Rene and Patty!, MUCH MUCH longer than my hangs for the same dives) for my tastes (IMHO longer hangs are NOT necessarily safer, they may reduce chances of DCI but longer hangs increase chances of other issues).. I know how MY body reacts to various profiles, but obviously its not a valid comparison for others..

The explorer in both OC and CCR mode is slower than both Gap (nominal and +1) and B.W. tables (the NAUI/B.W. tables scare me!).. I usually run the explorer at a setting of "1" and my HH at 10/100, on shallow dives the HH clears quicker than the explorer but on deep long dives the Explorer clears first.. The Cochran clears well after both of them..

I don't typically do what I consider bounce dives (where data is sketchy and ascent/decsent rates can really alter things) Thats why I qualified my dives since I DO see a difference on short dives (anything under 30-45 minutes at depth) vs long dives... On my "normal" dives I usually end up violating the cochran on either the 12m or 9m stops, on short dives Its usually fairly close..


When I was testing (before release) the 3 fo2/ 2po2 emc-20h, I had it set to OC with 3 mixes to approximate 3 reasonable switches and compared it to constant po2 vs my other computers (sset in both oc and ccr mode) and a 2 mix emc-20h, the differences were quite noticable between the cochrans.. I would still like them to make the 0 setting more agressive since there is a lot of adjustmant towards more conservatism that can be added.

I know last year you got a first hand look how us CCR divers view what bottom time should be..