When it comes to choosing a dive computer you want to make sure you are spending your money wisely, after all these are one of the most expensive purchases you make as a diver!
A dive computer allows divers to extend their time and safety while in the water. Considered essential by most dive centers around the world today your dive computer should be one of the first things you should buy. Since back in the 1980’s dive computers have been revolutionizing the way that we dive. Before the dive computer came along you would calculate your dive time based on the maximum depth you were diving to. The dive computer changed this significantly by being able to calculate your max dive time based on the actual dive allowing multi-level diving. Modern dive computers update you constantly on how much time you have left, based on your current depth. Essentially this allows you to remain underwater for longer in safety with potentially shorter safety stops.
Put simply dive computers use a depth sensor and a timer to work out how fast you absorb gases into your body by using an algorithm inside them. The deeper and longer you stay down the faster you absorb the gases you’re breathing and your computer monitors your depth and time at all times. Your dive computer keeps you safe and has multiple alarms to let you know if you go down too deep, ascend too fast or if you have an air integrated computer it will even tell you how long your air will last. When you ascend during a dive your computer will automatically go into a safety stop and tell you what depth to stay at and count down how long for. Most computers today alarm when you do something wrong like ascend too fast or stay down too long so you can concentrate more on the dive at hand.
Pretty much all dive computers today come with Nitrox algorithms so you can swap between air and nitrox. These computers can be set to different levels of O2% and some can even handle multiple values during the same dive if you dive with multiple mixes. Trimix is the next level by adding Helium to the mix and requires further training before you can dive safely on it. If you’re thinking of progressing to far deeper depths then a trimix computer is a consideration.
There are various different decompression models coded into hundreds of wearable dive computers around the world that will work out your Nitrogen loading based on your dive profile but they won’t give the same results as one will be more conservative than others or use a decompression theory. Because of this if you’re diving with a computer different to your buddy you can be waiting around for them to end a safety stop or forced to ascend because they are reaching their No Decompression Limit (NDL) faster than you are.
Most computers will have a conservatism factor that you can change because not all divers are the same. Algorithms are fairly generic and everybody is slightly different when it comes to fitness and body composition so you can tell some computers to be more or less conservative based on your body as well as altitude of the dive too.
Choosing a Dive Computer.
When choosing your computer you can opt for a wrist mounted display or a console display. Generally we’d recommend the wrist mounted computers but console mounted computers tend to be cheaper. There are arguments for both systems but here are a couple of points you should consider before deciding which would suit you best: Console mounted computers are larger and are attached to your regulator via a hose. This makes them less likely to be mislaid and easier to read. Console mounted computers use battery power even if only training in the pool meaning the more you practice, the more you will spend on batteries or having to recharge but a pool dive can lock you out of your computer for 24-48hrs for rapid ascent. A console mounted dive computer is not necessarily an air integrated dive computer but many are. The pressure gauge in your console requires a connection to your tank in order to show a pressure reading, but this does not mean that the computer is connected to the air source too, some dive computers can be mounted to a console next to a traditional SPG.
Wrist computers strap to your arm and are either a large screen or watch sized. Watched size computers can be worn after the dive day to day but have smaller screens so large screen computers can be easier to read. Wrist mounted computers can be used for other purposes such as free diving swimming and other sports. Some computers are solely made for apnea freediving and don’t have the same alarms and algorithms as most dive computers.
If you are interested in investing in a computer pop into Drift, our high street retail store, and ask to speak to Robin who can help you out with his recommendations for choosing a dive computer for the type of diving you plan on doing for the budget you have set aside. There are so many to choose from so do your homework, have a chat with your Instructor & listen to what Robin says. After all he didn’t get the reputation for being the best Scuba Retailer in the land for selling lemons!
