These days, you’ll be hard-pressed to find a diver willing to venture out for a day of scuba diving without the benefit of a dive computer. And that makes sense. The modern personal scuba dive computer’s ability to monitor depth and bottom time, track nitrogen loading, calculate decompression and so much more, helps make scuba diving safer, easier, and a lot more fun.
As with computers in general, over the course of the last three decades the diving computer has evolved into a powerful data center capable of monitoring virtually everything having to do with the diving experience. Available in a myriad of models, from the most basic data cruncher to the highly-advanced, feature-rich, computing powerhouse, offered in everything from compact wristwatch-styles to big-screen console computers, in today’s scuba dive computer marketplace you can find a model that will fit virtually every budget, skill level and diving style.
What is a Dive Computer?
Cutting through all the cool features, color screens and stunning graphics, a diving computer’s primary job is to monitor your critical dive data – depth, bottom time, ascent rates – while at the same time calculating and displaying your no-decompression limits so you won’t find yourself in a decompression situation. And if, either by accident or intention, you do end up in a decompression situation, your scuba computer will also provide you with a plan – using a series of timed deco stops – to work your way out of it, thereby avoiding decompression sickness (DCS).
In short, scuba diving computers are designed to keep you within the safety limits of your dive. If you monitor the data and make the right decisions based on what the dive computer is telling you, you should be able to stay within your dive “safety zone” with little to no difficulty and enjoy years of underwater adventures
Computers with Air Integration
The Dive Console Computer
A console dive computer is perhaps the most traditional of styles because it is designed to replace the old-time gauge console that held an analog pressure gauge, depth gauge, and perhaps a compass. The new fully digitized console dive computer incorporates all dive data, plus tank pressure, plus a digital compass, in a single, easy-to-use computing package. The better console computers, like the Galileo G2C and Aladin H Matrix, come with a convenient quick-release fitting that enables you to disconnect the computer console from the high-pressure hose for easy data downloading, safe transport and storage.
The Dive Wrist Computer
Wrist-mount diving computers feature contoured casing designs that virtually mold themselves to a diver’s forearm. While compact and low-profile, they provide large screens with easy-to-read alpha-numerics. All dive info is readily available at a glance, and after the dive they can be unstrapped and safely packed away. Some wrist-mount scuba computers, like the G2 Wrist and Galileo Luna, offer wireless air integration that monitors tank pressure, provides true remaining bottom time (RBT) and allows air consumption to be factored into the decompression calculation. These systems replace the high-pressure hose with a compact transmitter that screws into your first stage and sends psi/bar data via radio signals to the computer mounted on your wrist.
The Hands-Free Dive Computer
The Galileo HUD Dive Computer is an advanced mask-mounted, hands-free dive computer designed to keep you fully enthralled in your dive, so you can experience more freedom on your dive. Featuring a virtual, floating heads-up display that uses precision near-eye optics, it keeps your important dive information right in front of you. Using the simple push-wheel knob, you can quickly navigate the customizable menu without having to look away, and the screen conveniently tilts up and out of the way before or after a dive, or any time you don’t need it.
The Dive Watch Computer
Combining a topside wristwatch design with an underwater computer, these models offer a stylish timepiece that can be worn to work all week, along with a fully functional dive computer that can be taken under water on the weekends when scuba diving. Although small, these computers, like the fully-loaded M2 and solar-powered Z1, pack a lot of computing punch, and many divers find their ability to perform double-duty both topside and underwater to be a huge convenience.
The Wrist Computer
These units come in a larger format and are extremely rugged. They are usually worn on the wrist with a HD rubber strap or even bungee cords, but they can replace a depth gauge in a traditional instrument console. The easy to use Aladin One Matrix is an ideal computer for new divers, and a great backup once you’ve moved to more advanced dive computing. If you’re looking for a wrist unit to handle technical diving or want a digital compass the Aladin Sport Matrix would get the job done
Essential Features of a Diving Computer
All modern scuba dive computers are, in essence, the same, in that they all calculate and display no-decompression limits (NDLs) to help you avoid slipping into a decompression situation. All dive computers also monitor current depth, maximum depth and bottom time; provide current time and temperature; program nitrox mixes; monitor ascent rates and provide guidelines for performing safety stops; plus all dive computers employ a series of audible and/or visual alarms to make sure you’re paying attention.
What sets scuba dive computers apart from each other are the additional features and functions they provide – along with the methods in which they deliver all of this information.
The Differences are in the Details
• First and foremost, a good dive computer is user friendly. If data can’t be easily accessed and understood, then that data is wasted. Good dive computers offer intuitive menus and simple button functions – with labels – that enable you to navigate through the system, set parameters, and easily access data.
• The size and design of the display is important. The size of the screen, the layout of the display, the clarity of the alpha-numerics and graphics, the use of color and having an effective backlight all contribute to the ease of seeing and understanding the data the dive computer is providing.
• Air integration is convenient, plus enhances calculations. Having tank pressure displayed on the same screen as your other data makes easy work of monitoring your dives. Also, air integration enables some computers to provide “Air Time Remaining” data, plus allows computers like SCUBAPRO’s air integrated models to factor air consumption as workload into the algorithm calculations.
• Nitrox & Multiple Gas Mixes. While virtually all modern dive computers are capable of programming nitrox mixes (either 21-50% or 21-100%), the more advanced dive computers can program multiple nitrox mixes that can be switched at depth (for example, one mix for diving, and one mix for performing safety stops). Others, like the G2 are capable of programming trimix, plus are CCR (close-circuit rebreather) and Sidemount system compatible.
• Algorithms to match your diving style. A scuba computer’s algorithm determines its liberal or conservative leanings. Conservative-leaning algorithms limit the amount of time you can spend at depth without putting the computer into deco mode, but help increase your safety margin. Liberal-leaning algorithms allow much more bottom time before going into deco mode, but by doing so can increase your risk of DCS (decompression sickness).