Dive Computer Buying Guide
Once considered a luxury item for cashed up divers, dive computers now come in so many configurations and price ranges, that any diver can afford one. As divers, we know that the consequences of breaking the depth/time rules can result in decompression sickness with varying levels of severity. Dive computers make up part of your life support system when underwater and help ensure you are diving in maximum safety, by performing the calculations that you would normally work out manually using your dive tables. They are constantly monitoring all the crucial data, processing it and providing the appropriate information to the diver in real time, when sometimes every second counts. Whether you are making your first venture into the sport of diving or you’re a more experienced diver looking to upgrade, it can be a daunting task to choose a dive computer, but if you take into consideration all of your individual requirements and make an informed choice, it’s a purchase you won’t have to make again for a long time!
So what should you look for when buying a dive computer? There are a number of basic features that every dive computer performs regardless of brand or price, so what you need to consider are the other features which may be of importance to you according to the sort of diving you intend to do. Some of these are outlined below:
Readability and Backlighting
Dive computers which have large digital displays and backlighting on demand are perfect if you have any concerns about being able to read them easily while underwater, or if you think some of your dives might be in low light environments, such as night diving or cave diving. Some of the computers in the top-end of the Suunto line, including the Suunto D6 and Suunto D9, have user programmable backlighting so you can choose how long it illuminates for, while the Suunto Zoop uses phosphorescent backlighting which can be activated using your dive torch.
Do you prefer a wrist mounted unit or perhaps even a model that also doubles as a watch? The Suunto D series watch-sized dive computers (D4i, D6 and D9) are very classy options which look and work as well on the surface as they do underwater. The Mares Puck gives you both options – simply choose your preferred configuration. If you prefer the more traditional console mounted computers, the Mares Puck Air is worth looking at; as well as being sleek and streamlined it offers a range of advanced features.
Perhaps your biggest consideration is simplicity and effortless, straightforward operation. You’ll find dive computers on the market that come with up to 4 buttons, and can use some pretty weird button combinations to set the required parameters. Computers like the Oceanic Veo 100 and the Mares Puck however have a single button operation and are designed to be logical and intuitive to use.
User Changeable batteries
User changeable batteries are highly important as well, after all, who wants to get left on the boat because the battery’s low and the whole computer needs to be sent away to have it changed! Some current models which offer this functionality are the Cressi Sub Archimede II, the Oceanic Veo 100 the Mares Puck Air or the Suunto Zoop.
Do you want a computer which is water activated in case you forget to turn it on, or is an integrated compass an important feature for you? Many models come with water activation, including the Oceanic Veo 100 and the Oceanic VT3, while the Suunto D6 has water activation as well as an integrated compass.
Air or Nitrox
Even some of the most basic dive computers come with both Air and Nitrox capabilities, such as the Aeris XR1 Nx, and they can perform all the functions a diver just starting out in the sport requires to dive with safety, with the added option of participating in Nitrox dives if desired, and if trained correctly of course. We all know that too much nitrogen in our tissues while diving can cause decompression sickness. Nitrox is any gas blend of more than 21% oxygen, so Nitrox diving allows you to reduce the amount of nitrogen in the breathing gas to counteract how much is absorbed during dives. It can also increase bottom times and shorten surface intervals, as well as increasing the number of dives safely achievable in a day. If you want to take your diving to the next level, and obtain even faster desaturation and decompressions times, you might want to consider a computer which can utilise more than one gas mix such as the Suunto D6, or the Cressi Sub Archimede II which allow you to switch between 2 programmable Nitrox mixes, or the Oceanic VT3 which has up to 3 gas mixes. All the computers mentioned in this section allow you to choose between Air and Nitrox for your breathing gas, but it’s an individual choice and Nitrox diving certainly isn’t for everyone as it also poses some additional problems that you don’t get when diving with Air such as oxygen toxicity.
Air integration is yet another feature to think about as it not only provides you with the standard depth and time data, but also tank pressure and Air Time Remaining readings, which can help you more accurately execute the dive. The Mares Puck Air has air integration with the capability of using 1 Nitrox mix, while the Suunto D9 has air integration and allows for gas switching for up to 3 mixes. Wireless air integration is another factor; these air integrated computers have a transmitter which replaces your high pressure hose with the Oceanic VT3 being a perfect example.
Monitoring other tank pressures
Some computers such as the Oceanic VT3 give you the option of purchasing extra wireless transmitters which can be installed on subsequent tanks, allowing you to monitor the pressure of up to 3 tanks; either your own decompression or pony bottles or up to 2 of your dive buddies tanks.
Traditional dive tables allow you to graphically map your dives using depth and bottom time to perform calculations which decrease the chance of decompression sickness. These calculations also help plan any repetitive dives and the surface interval required before conducting them. Dive computers contain algorithms which perform the same function, and are broadly categorised as ‘liberal’ or ‘conservative’, with conservative having more built in safety which directly relates to your no decompression limits. You might want to go for a more liberal profile such as the one which the Oceanic VT3 uses, or perhaps a model which allows you to reduce the algorithms from 100% to 50%, such as the Suunto D6, D9 and Vyper Air. Most dive computers are considered to generally have more conservative algorithms, which ultimately means safer diving.
Surface Mode/Pc Interface
Think also about how you want to analyse your dive data once you’re on the surface; is the on board dive log sufficient for your needs or do you require a Pc interface so you can download your dive data to your computer and analyse it in more detail. Maybe you even require a dive simulator so you can test potential dives before you take the plunge. The Cressi Archimede II has an optional Pc interface while the The Suunto D9 has an included Pc interface, and the Suunto Vyper Air has a built in dive simulator as well as an optional Pc interface.
As the functionality of the many dive computers available today varies, so do the price ranges, and for most people price is going to be high on the list of priorites when the time comes to purchase or upgrade. Options to consider if you want a dive computer that is feature rich and affordable are the Aeris XR1 Nx or the Mares Puck Air, both which include different functionalities but offer exceptional value for money. In the mid price range the Cressi sub Archimede II is in the lower end of the range, whereas the Suunto D6 or Suunto Vyper Air sit at the higher end of this range. If price is not your first priority and you’d rather pay a bit more for a wide range of functions to choose from, you can’t go past the Oceanic VT3.
As you can see, there are a lot of things to take into account when you’re shopping for a dive computer, as the many models available cater for differing levels of ability, serve different purposes and satisfy different diving requirements. Thinking about not only what sort of diving you are enjoying today, but what you might like to do in the future will go a long way towards narrowing down your choices, and help you to ultimately choose a computer which will serve you well for years to come.