Choosing a dive computer in some ways is a pretty straight-forward process. You decide on a budget and go for it, because most of them are very good, and amazingly inexpensive considering what they do and how well they stand up against submersion in salt water.
For most divers, just about any computer that is easy to read and use will do the job, because for most divers their computer serves one primary purpose; to keep the diver out of decompression. One such dive computer is the SubGear XP10 that I reviewed briefly in an earlier post. Another is the Oceanic Datamax, which I also own.
Both of these, as well as every other dive computer, provide the diver with decompression information should he or she stay at any given depth too long. As a result, there is a tendency to view these as decompression computers. However, they are not intended as such.
A decompression computer provides decompression information to divers intending to perform decompression dives. Therefore, they provide the diver with the ability to control variables like decompression/bubble models, conservatism, and multiple breathing gasses.
For those of us who regularly make decompression dives, sport diving computers are usually a poor choice because they offer no way for the diver to adjust the model. Instead, they typically are programmed using the most conservative possible algorithm. At first glance, that seems perfectly reasonable, but for serious decompression dives, most of those computers are so conservative that you may not have the gas to complete the dive.
Also, many of those computers simply lock up, preventing additional dives, once a decompression stop has been required. So, if there’s the possibility that technical diving involving decompression is in your future, be sure to choose a dive computer that will support you as you grow.