You know, every time I hear or read the name "Cochran," I think of a fictional Star Trek character who invented warp drive. Yeah, I'm a Trekkie. What amazed me was how something so complicated could be made to function with such ease of operation. The same is true of the Cochran EMC-20H Dive Computer; it does an awful lot, but the user interface is so simple that even if you don't read the directions, you can still use it--just get it wet. That's NOT to say that you shouldn't read the directions. As with any dive computer (or other technology) there is a learning curve. If you want to get all of the performance you can out of this 'puter, then you need to read and understand the manual first. If you're not someone who likes to sit and read directions while pushing buttons--or in this case, shorting contacts--then the PowerPoint tutorial for the software helps you along. Yes, I said "Software." This dive computer, like many today, allows you to manipulate settings and gather dive data by connecting it to your PC.
Now, before I go much further, let me explain why this review is even here: I can think of two reasons...
- Because there are plenty of public safety personnel whose duties require them to work underwater, and
- Because there are plenty of public safety personnel who enjoy scuba diving off duty.
So that you can easily judge size as it's worn, the Cochran EMC-20H is shown here, just before a dive. While not small, it's not uncomfortably big or ungainly. Then again, it does an awful lot more than the average hockey puck or "wrist top" computer.
There was a time that I'd say this was more computer than any recreational or even typical public safety diver would ever need, but no longer. In today's world of truly deep divers (past the 200-foot mark), divers using different Nitrox blends every other dive and so on, a computer has to be carefully designed, flexible in its programming and capable of meeting all demands, while maintaining a good safety margin.
One of the great things about the Cochran is that it already meets the military standards for no-decompression, planned decompression and repetitive diving. On top of that, the diver can preprogram it to be even more conservative. Why any diver would want to be MORE conservative, thereby reducing his bottom time, may not make sense, but there are folks who do. Just to test the capabilities of the computer, I did that this past weekend. I set it to be 10% more conservative. In comparing the no-deco times between the Cochran, my wife's dive computer, and a wrist top computer we had on hand (actually, "on wrist"), the remaining no-decompression times were all within a couple of minutes of each other. Given the number of algorithms that are out there and being used to determine safe no-decompression limits, it wouldn't have surprised me if the remaining no-deco times had varied quite a bit.
All of the programming, unless you have the unit connected to a PC, is done through shorting out two of the three contacts on the side. There are no buttons to push. The arrangement of contacts is shown to the right in this diagram. I am amazed, although I guess I shouldn't be, at the Cochran's ability to determine whether the contacts are being shorted with metal, a wet finger, fresh water, salt water or the PC connector. Obviously, if you're going to attempt to program anything before you use the Cochran, you need to read the manual. If you connect it to your PC and go through the tutorial, you'll also be in good shape.
Like every contemporary wrist-worn computer that isn't downsized in an attempt to resemble a watch, the Cochran has a curved back specifically set up to hold it in place on top of your wrist/arm. I'm an average size guy, and it fit my wrist just perfectly over my 3mm suit (5mm torso, 3mm extremities). For larger guys, or when wearing a thicker suit, the curve might not mold so perfectly, but thankfully neoprene is soft and pliable.