Citizen Cyber Aqualand

[mikerault]

I have been diving the NX for my last few dives. Yes, the Canada algorithm is a bit more conservative, why they choose that I'll not guess. However, I have not had any issues with it and I like the download features as well as its compact size. However, the strap is a bit tight for a 7mm semi-dry suit so I usually clip it to my BC. I use my Cochran Commander for a backup.

Mike

 

[scubadobadoo]

I don't know much about the DCIEM algorithm, but it seems to approach the square profile in conservatism.

Thanks again for the links and the info and your interest in helping me figure this out.

---Bob

My pleasure. I was hoping my comments didn't come off as accusatory or negative in my second post. I was just thinking out loud. You know what I mean, lol. I also don't know much about the DCIEM other than the few comments on the above thread and a few others.

 

[mikerault]

From an article in Scuba Diving Magazine:

THE BASE ALGORITHM: DCIEM
Developed by the Canadian Defense and Civil Institute of Environmental Medicine (DCIEM), this algorithm is unusual because it assumes only four tissue compartments and because it assumes that dissolved gas passes from your blood to your fastest tissue, and from it to the next fastest, and so on. Haldane and other theories assume gas passes from blood to each compartment directly.

The full article is here:

http://www.scubadiving.com/gear/dive_computers/crunching_the_numbers/7/

Mike

 

[mikerault]

And from a cave diving site:

DCIEM (Defense and Civil Institute of Environmental Medicine): Decompression dive tables from Canada. The DCIEM decompression theory is based on the Kid-Stubbs model, which was developed in 1962 according to U.S. Navy dive tables and considering multi- level and repetitive dives. Their approach was to dive the model and, when symptoms of DCS occurred, to change the parameters of the model making it more conservative. They went through several variations of their air decompression model, improving the safety of the model with each iteration. They came to realize that the human body is better represented by a series arrangement of tissues. By 1967, over 5,000 experimental dives had been conducted to validate the K-S (Kidd-Stubbs) model. In 1971, the K-S decompression model was approved in Canada as a safer alternative to the U.S. Navy tables. In 1979, DCIEM initiated a critical reevaluation of the K-S model using digital computers to control the dives and specially-designed Doppler ultrasonic bubble detectors to evaluate the severity of the dive profiles. Then, thousands of verification dives and many improvements of the theory were made and the dive table for air diving was released in 1992. The present DCIEM theory is represented in this dive table.

http://cavediver.net/archives/glossary/lex_htm.html

Mike

 

[mikerault]

AN article which shows comparisons between models:

http://www.diverssupport.com/Times3.htm

And another that talks about the computers:

http://home.att.ne.jp/star/divehard/HardGear.html

As a point of comparison my Cyberland NX gave NDLS for 60, 100 and 130 feets as 45, 13 and 7 minutes, which are even more restrictive than indicated by the DCEIM algorithm.

Mike

 

[scubadobadoo]

good digging mike, thanks.

 

[PapaBob]

Wow! Mike & Cool, great info!

Battery: I was diving air and the watch was set to air (default setting).

Scubadobadoo: Yeah, a while back I posted a response that I intended to be helpful but when I went back to reread it I had an unintended critical tone. I am sure the recipient thought I was a donkey crater. Its tough communicating in a forum without the benefit of body language and vocal inflection. Smilies are of limited use IMO. My rule is to always give the poster the benefit of the doubt and the interpretration that is kind rather than mean spirited. The vast majority of board members are well intentioned and there is so little flaming in this forum. I am sure Pete and Ted stomp on any really nasty stuff before it gets too far.

---Bob