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.

One benefit of the large rectangular screen is the ease with which everything can be read--even under water. The diagram shown right here gives an example of what is shown during a surface interval (between dives). The two most common pieces of information displayed are the length of surface interval and the amount of time remaining before the diver can safely fly. In this case, the Cochran also shows how many dives have been completed that day, the bottom time from the last dive, and the maximum depth of the last dive. The temperature is also displayed and changes for in-water versus out-of-water. It takes only a moment or two for it to change, and I was impressed with how quickly it did so. Note that in this diagram the temperature and the maximum depth are displayed in metric--Celsius and meters. The Cochran can be easily set for Imperial (Fahrenheit and feet) which is how mine was set before diving.

But more important than how the computer appears during surface intervals is how it appears while diving. While the diagram shown is actually from the computer's "log book" mode, the display is about the same as it is during a dive. No-decompression time remaining, bottom time, water temperature, current depth and ascent rate are all there. The difference is that, instead of a surface interval time, there is a partial pressure reading based on the single gas mixture you're diving.

This is where I get to tell you that this computer will handle computations for as many as three different gases on a single dive. Most will handle one or maybe two, but three gases and helium in a single dive? That takes some computing power.

The second screen shows important information about your oxygen toxicity levels. Virtually all divers who dive anything beyond regular air (Nitrox, anyone?) needs to know this information. While we all should be able to do the calculations using the dive tables and keep track of the various data points, having a computer that does it all for us and that delivers the information in an easy to read format makes it all the better. AND, if you use the Dive Analyst software, it's even easier to download the information to your PC.

With all of the above said, if you simply take the Cochran out of its hard case, strap it onto your wrist and go diving, you'll be okay, provided you're using regular air. It's preset for air at the factory. The information provided during a normal dive is easy to read and clearly labeled. When you decide to learn more about it, the dives are stored so you can extract them later. When you expand your skills and start doing deep dives, Nitrox dives, or multiple gas blends, the computer is still capable. You won't have to go out and get another one.

Admittedly this isn't a thorough "wring out" of this computer. I had intended to dive at least one Nitrox dive and wasn't able to. I had planned at least four dives this past weekend and only got in three. The test Cochran I had did everything it's supposed to when it was supposed to in a clear and easy-to-understand manner. When I got home, connecting it to the PC and extracting the dive data was pretty easy. Of course, I had to know what one of these costs new, so I did a search online. The price ranges were outlandish, and I highly recommend you spend some time looking and contacting dealers if you want one of these. It may simply be best to go through Cochran and have them recommend a reputable dealer. I found advertised prices ranging from $1,100 to over $3,600. The base models that don't do multiple mixed gases plus helium aren't quite as expensive.

I forgot to mention that the computers are available in seven different colors. My test unit was yellow, but black, green, gray, blue and other colors are available.

As I said, this isn't a thorough review. I will be doing some more diving and experimenting with the unit and will write it up from the more technical standpoint in the near future. In the meantime, to learn more about Cochran dive computers visit them online.


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