If you’ve recently learned to dive, you’re probably hunting for your first dive computer. There are many entry-level options on the market and you’re probably feeling a little overwhelmed by all the choices and technical terms. To help you find your first dive computer, we’ve put together a handy guide to all the key things you need to know.
What is an entry-level dive computer?
You’ll see the term entry-level often. This simply means that the dive computer is designed for and marketed to beginner divers.
Entry-level computers don’t have all the bells and whistles more expensive or technically advanced models have. But they do offer all the functionality a recreational diver needs.
Dive computer algorithms
Different dive computers and manufacturers favor different algorithms. An algorithm is a theoretical model that estimates how much dissolved gas your body loads during dives and offloads during surface intervals.
Suunto dominates the entry-level dive computer market. Their computers use Suunto’s version of the Reduced Gradient Bubble Model or RGBM for short. Mares and Cressi also favor this algorithm in their entry-level models.
The RGBM is the perfect choice for a new diver, as it’s a relatively conservative model that is well equipped to handle multiple dives over multiple days.
You might not be nitrox certified yet but if you continue diving, it’s highly likely you’ll pursue the certification. Nitrox or EANx — the terms are interchangeable — means Enriched Air Nitrox. It’s a gas mixture for diving that contains more oxygen and less nitrogen than your standard air tank. So, a diver might choose to dive with 32 percent or 36 percent O2 in their tank instead of the normal 20 percent in regular air tanks.
The primary benefit of diving nitrox is that it exposes you to less nitrogen — the other gas that makes up scuba tanks and the gas that governs your no-decompression limits and bottom times. A knock-on effect is longer allowable bottom times.
These days, almost all dive computers are nitrox compatible. Just double-check that the model you’re considering offers this functionality before you buy. Note that you only need O2 compatibility of up to 40 percent. Dive computers that support 100 percent O2 are for technical divers who use a higher percentage oxygen to accelerate their decompression.
Dive computer modes
Manufacturers list the modes their computers can operate in. These modes are pretty standard, and you’ll note that there is little variation among entry-level models.
Here are the modes you’ll see and what each means:
- Air — This mode is for standard scuba dives with a tank of air.
- EANx or nitrox — Use this mode when you’re diving nitrox.
- Gauge — In gauge mode, a computer acts as a bottom timer. It will display your time and depth but will not give you a bottom time or no-decompression limit.
- Freediving — Also called ‘Free,’ this mode is designed for no-tank, breath-hold diving. Choose a computer with a freediving mode if you’re also interested in this sport.
- Off — The computer is not tracking water exposure, depth, or time. This mode can be useful if you wear your computer like a watch and spend lots of time splashing around on the surface.
Computers with air integration allow you to pair your device to a wireless transmitter on your regulator’s first stage. The computer will then display how much air you have in your tank during the dive.
You still need to use a traditional air gauge during your dives though, just in case the transmitter fails. Entry-level computers with air integration are more expensive and you should also consider the cost of the transmitter.
A dive computer battery doesn’t last forever, and you will need to replace it at some point. Certain models allow you to do this yourself, while others require you to send the computer to the manufacturer or take it to a licensed service center.
If you prefer to change the battery yourself, choose a model that allows you to do so. Just know that making an error means you may void your warranty.
What about rechargeable batteries?
Rechargeable batteries are a good option and allow you to skirt the perils of changing your own battery and avoid taking your computer to the shop. That said, few entry-level computers have rechargeable batteries, possibly because of price considerations.
Does brand matter?
Yes and no. Some divers have a preference for one or two brands while other divers are happy to use gear from multiple manufacturers.
When it comes to computers, we recommend sticking to a well-known dive equipment brand. Below are some of the common brands you’ll see. All of these companies make reliable entry-level dive computers.
Watch style or classic?
Ask yourself what you will do with your dive computer. That might seem like a funny question because obviously you’ll go diving with it. But do you also want it to do double-duty as a daily watch?
If so, choose a smaller, watch-style dive computer. Classically styled models are large and chunky. They’re unmistakably a dive computer and might not be suitable for the office. If, on the other hand, you intend to wear the computer every day, choose a small, sleek model that doesn’t look out of place with your work outfit.