How to Compare Conservative Dive Computers
- 1). Contrast how conservative two dive computers are by comparing each computer's no decompression limit (NDL), or the amount of time a diver can spend underwater before he needs a decompression stop prior to resurfacing, and make these comparisons at the same depth. A dive computer with an NDL of 18 minutes at 100-feet is more conservative than one with an NDL of 21 minutes at the same depth. This information is the quickest, simplest way to cut to the chase when it comes to the algorithms used to calculate how much nitrogen your body has absorbed. However, NDLs are not always printed on the box or included in the manual, and listed NDLs may not match-up. In this case, contact the manufacturers.
- 2). Compare each NDL for nitrox, or oxygen-enriched gas, if the dive computers are equipped to calculate nitrogen absorption for nitrox. Some computers are not, and if you intend to use nitrox at all, you will want your computer to compute for both regular air and nitrox. Once again, a lower NDL means a more conservative computer.
- 3). Note the physical format of the dive computer. Dive computers come either as wrist-watch style devices or as consoles, which are mounted on a hose connected to the scuba regulator and air tank, just like an analog tank gauge. Console dive computers come with either an analog tank gauge or they are "air-integrated," meaning the computers also track air consumption. A Wrist-watch dive computer is usually separated from the air tank completely, although some may come with a wireless connection so that they too are air-integrated. Divers often prefer one or the other format, whichever is handiest, but this is strictly a matter of personal taste.
- 4). Compare the electronics features of the dive computers. Dive computers have memory and can store dive data, with eight to ten dives being the norm. Some computers can store as many as 40 dives. Most dive computers have a simple digital readout, while others have a more modern, computer-like color display. Finally, compare battery life and ease of replacement. A conservative dive computer should exhibit reliability and ease of use over flashy features.
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