The following was taken from
http://www.bikiniatoll.com/
Cochran Computers and Bikini Atoll
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NOTE [4/1/01]: We are very happy to report that if you have the NEW version of the software that Cochran puts in their dive computers they will work just fine on Bikini. Two weeks ago we had a group from the U.K. that had computers with both the new and old versions of the Cochran software. The old version failed like clockwork, the newer version, however, went through the entire week without a problem. Please consult your Cochran dealer to find out which version of the software your computer has.
NOTE [6/11/01]: Disregard all of the above. We have had some recent experiences with the new Cochran computers that actually had people wanting to get out of the water 10-20 minutes before their Deco time was up! This is according to our divemaster's Nitek3 computers that account for off-gassing at an accelerated rate for the 75% mix of oxygen. Quote from our divemaster : "The new Cochran computer is simply scary."
**Please understand that of you don't believe this and you show up with a Cochran computer--and it fails--you will have to rent a computer from us for the rest of the week for $65.00.
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A lot of divers have asked us about the fact that we do not recommend the Cochran Commander and Nemesis computers on our web site. This advice is posted because of our extensive experience with customers who have brought those models to Bikini--and the computers' subsequent failure to perform during a week of diving. If you check our website you will find an example of our diving profiles for the week and realize that we are not pushing any technical diving limits. We often decompress for longer than the tables or computers require and after four years our operation has never had to send anyone to a recompression chamber, which is a remarkable safety record for any dive program.
The problems encountered with the Cochran Commander and Nemesis computers are as follows:
1) The Nemesis II alpha has failed 100% of the time it has been brought to Bikini. The first time we saw one it was brought by our friend and instructor Kevin Denlay, who came in 1996 to teach us Technical Nitrox courses. His unit failed on the 3rd day. He was pretty upset. The unit simply locked up and would not allow him to dive--unless he removed the batteries. This procedure is not recommended for some very obvious reasons, not the least of which is that it is simply an unsafe practice. All other Nemesis units brought to Bikini presented the exact same problem. Cochran's response to these customers implied that our diving profiles are unsafe and that our customers were not competent enough to properly use their product. We do not think it a safe nor a fair policy to blame computer failure on the diver. Click here to check their response to the "Bikini Atoll" question on the Cochran website. Their statements on this site are, to say the least, misleading.
2) The Commander Nitrox had a little better luck: Nearly 80% of the units brought failed to survive the entire week without showing some very apparent problems. One thing struck us as very odd: while some customers were wearing two Commander Nitrox units for redundancy--and programming those units with the very same information--they would invariably have one of the units fail on them.
One particular episode that really annoyed our dive team on Bikini was when we had a diver hanging at the 30 foot decompression stop after all his other fellow divers were clear on their computers and were already hanging at 20 feet. I decided to go down and check his profile and found that although he had dove the same profile as everyone else ( depth + time ) his Commander still had a decompression obligation of 9 hours! Perhaps some people might think that we don't know that these machines will credit the use of oxygen enriched mixtures for deco by accelerating the clock. By this I mean that the minutes of decompression left will go faster than a real clock, thus giving you less time in the water. That was *not the case* as after 30 minutes at 30 feet he still had 6 hours to go! This information is incorect to start with. You can run tables with any algorithms on our profiles and see that a 9 hour decompression obligation is never required. And this has happened more than once and with different users. Nobody had more than 6 minutes of decompression time at the 30 feet stop on that dive and the average total deco for the dive was 45 minutes. I had to ask that diver to finish his decompression obligation on tables.
If your computer does not work on Bikini, it will then have to be used in depth gauge mode. Therefore, you might as well bring digital depth gauges instead, after all they are a lot cheaper.
Cochran has a new model out and I hope these kinds of problems do not develop. So far we have no experience with the Cochran Genesis, their newest model. I will gladly recommend their product once it passes our tests, and that means real life tests with customers doing all the dives for the week without computer failure.
I also want to state here that we at Bikini hold nothing against Cochran as a company. We will recommend any of their products that pass our tests. We make the pledge that our website will be updated as soon as this happens. I also want to remind you that Cochran is not the only brand that presented problems for divers on Bikini. Again, here is our "not recommended" list:
Cochran Nemesis and Commander computers
All Oceanic computers
Source computers
U.S. Divers Matrix computers
Scuba Pro DC 12 computers
"Edge" from Orca
"B'Air" from Dive-Rite
If you own a dive computer ( any brand ) and have encountered some of the problems described above, please e-mail us and tell us of your experience. Maybe we can start a forum for keeping track of these problems, and who knows, perhaps we can help the industry on future developments in the realm of technical diving computers.
Have fun diving and I hope to see you on Bikini Atoll in the near future.