Whether you are new to scuba diving or if you have been diving for a while and are looking to buying your first dive computer, in this ultimate guide I will cover everything you should know when buying a dive computer.
A dive computer is an essential tool that should be part of every diver’s scuba equipment. It’s a device that helps you keep track of your depth, bottom time, ascent rate, and other crucial information that can affect your safety while diving.
In this guide, we’ll take a closer look at dive computers, discuss the factors to consider when choosing one, and provide recommendations based on your experience level and diving environment.
If you are undecided on which scuba gear you should rent or buy, a dive computer is definitely one of the pieces of your dive equipment you want to own.
Understanding How Dive Computers Work
Before entering into the specifics of buying a dive computer, let’s first understand what a dive computer actually is and and how it works.
Simply put, a dive computer is a small electronic device that displays real-time information about your dive. It calculates your current depth, remaining bottom time, ascent rate, safety stop time, and warns you if you exceed the limits of a safe dive. This information is crucial irrespective of whether you are into recreational diving or technical diving.
There are three types of dive computers: wrist-mounted, console-mounted, and watch-style.
Wrist-mounted dive computers are worn like a watch and are the most popular type. They are easy to use, compact, and can be worn on the surface and during the dive. They are popular with recreational and technical divers alike.
Watch-style dive computers are relatively new to the market and are designed to look like regular watches. They are small and lightweight, making them an excellent option for travel. They are most popular with vacation divers or with divers that need a backup computer.
Console-mounted dive computers are attached to your regulator and show the same information as a wrist computer. They are typically more expensive but offer additional features such as air integration (they indicate the exact amount of residual air in your tank). Note that console-mounted dive computers are generally more delicate and provide more drag than wrist computers and watch style computers. This is particularly the case if they are not properly tugged in your buoyancy control device.
Dive Computer Features
When looking for a dive computer, there are certain essential features that you should consider. These features will ensure that you have a safe and enjoyable dive.
Dive Time
A good dive computer should measure your dive time accurately. This feature is important for tracking how long you have been underwater and calculating your decompression or safety stops.
Some of the more advanced dive computers automatically recalculate your dive time in case you exceed your no decompression limit.
Depth Gauge
A depth gauge is an essential feature that tells you how deep you are diving. This feature helps you monitor your dive profile and avoid exceeding your maximum depth limit.
Depth gauges are an essential element of your dive gear and having one integrated in your dive computer comes quite handy.
Ascent Rate
Ascent rate is the speed at which you ascend to the surface. A good dive computer will measure your ascent rate and provide alerts if you ascend too quickly. This feature helps you avoid decompression sickness.
Nitrogen Loading
Nitrogen loading refers to the amount of nitrogen that has been absorbed by your body during a dive. A good dive computer will monitor your nitrogen loading and provide alerts if you exceed safe limits. This feature also helps you avoid decompression sickness.
Note that in almost all cases, nitrogen loading is approximated thanks to decompression algorithms. The nitrogen loading displayed by your dive computer might not be the exact level of nitrogen loading you are exposed to.
Decompression Stops
Decompression stops are mandatory stops that a diver must make during ascent to allow nitrogen to safely escape the body. A good dive computer will calculate the necessary decompression stops based on your dive profile.
Although decompression stops are more for technical rather than recreational divers, note that the safety stop you do at the end of every dive is actually a decompression stop.
Audible Alarms
Audible alarms are essential safety features that alert you to critical information during a dive. Some dive computers will provide audible alarms for important information such as ascent rate, decompression stops, and low battery.
I am personally not a fan of audible alarms, as they might over-alert you and divers around you even in case there is no real emergency. I prefer vibration alarms rather than audible alarms. If you are looking for a dive computer with alarms and alerts, check out my list of the 10 best dive computers with integrated alerts.
Backlight
A backlight is an essential feature that makes it easy to read your dive computer in low light conditions. This feature is particularly important for night dives and for low visibility environments.
Even if you plan to dive mostly in tropical locations with high visibility, a computer display with backlight is essential in case you are planning to do some night diving or in case you are diving during a cloudy day.
Logbook
A logbook is a useful feature that allows you to record your dive data for future reference. This feature allows you to keep track of your dive history, including dive time, maximum depth, and nitrogen loading.
Although you can definitely keep a “pen and paper” loogbook, having one in your dive computer is quite handy. Particularly if you are doing multiple dives per day and do not want to spend time logging your dives every time you are back to the surface.
Air Integration
Air integration is a feature that allows your dive computer to monitor your tank pressure and calculate your remaining air time. This feature is particularly useful for longer dives and technical diving.
As we saw earlier, console-type computers come with air integration. Watch-style and wrist-mounted computers can still have an air integration system thanks to some transmitters that are mounted directly on your first stage.
Note that transmitters are usually sold separately.
Modes
Most dive computers offer different modes such as air, nitrox, gauge, and free dive. Air mode is for diving with regular air tanks, while nitrox mode is for diving with enriched air. Gauge mode is used for measuring depth and time, while free dive mode is for measuring dives without tanks.
Compass
A compass is a useful feature that allows you to navigate underwater. A good dive computer will include a digital compass to help you find your way.
Note that a compass is a required piece of scuba gear, particularly if you are diving in a low visibility environment. Having one integrated in your computer will spare you the money of buying a separate compass.
These are some of the essential features that you should look for in a dive computer. It’s important to choose a dive computer that has the features that are most important for your diving needs.
Factors You Should Consider When Buying A Dive Computer
Budget
The average price of a dive computer can vary depending on the features and capabilities of the unit. Basic entry-level dive computers can start at around $200, while more advanced models with additional features such as air integration and multiple gas capability can cost upwards of $1,400 or more.
However, there are also mid-range dive computers available in the $300-$500 price range that offer a good balance of features and affordability for recreational divers.
It’s important to keep in mind that while cost is certainly a consideration when choosing a dive computer, it’s also important to choose a unit that meets your specific (current and future) diving needs and provides accurate and reliable data to help ensure a safe and enjoyable dive.
Experience Level
Your experience level is also an important factor to consider when buying a dive computer. If you’re a beginner diver, you may not need a high-end dive computer with all the bells and whistles.
A basic wrist-mounted dive computer will likely suffice. However, if you’re an advanced or technical diver, or are planning on becoming one, you may need a more advanced dive computer with features like trimix or even rebreather compatibility.
Diving Environment
Consider where you’ll be diving most often. If you’re primarily diving in warm, clear water, a basic dive computer will likely suffice.
But if you’re diving in colder, darker water, you may need a dive computer with a larger display or a backlight. If you’re diving at high altitudes or in caves, you may need a specialized dive computer designed for those environments.
Maintenance and Care
Like for every piece of scuba gear you purchase, maintainance and care for dive computers should also be taken into account when buying one.
While the exact maintanance and care requirements are specified in each computer owner’s manual, there are some elements you may want to consider befor buying your own dive computer.
For example some computers have rechargeable batteries whereas some others have disposable batteries that can only be changed in specialised dive shops.
If you plan on diving mostly on holidays, you want to buy a dive computer with rechargeable batteries or with disposable batteries that you can change by yourself. In some situations, like on a liveaboard trip, it’s quite difficult to find a local dive shop that can change your computer’s batteries.
Besides the possibility to change the batteries by yourself, once you’ve bought your dive computer, it’s essential to properly maintain and care for it to ensure it lasts as long as possible. Here are some tips for caring for your dive computer:
- Rinse your dive computer with fresh water after each dive and dry it thoroughly.
- Store your dive computer in a cool, dry place, away from direct sunlight.
- Avoid dropping or knocking your dive computer against hard surfaces.
- Have your dive computer serviced regularly by a professional.
The last point is particularly important and that is why i suggest to buy a dive computer that your local dive shop is able to service.
Conclusion
A dive computer is an essential tool for any scuba diver, and finding the right one can make quite a difference in your diving experience. Consider your budget, experience level, and diving environment when choosing a dive computer, and don’t forget to properly maintain and care for it.
Among all the scuba gear you will buy, a dive computer is most likely one of the most important and valuable pieces of equipment. Investing in the right dive computer from the very beginning will help you spare some money, besides making your diving more enjoyable and safe.
Dive Computers FAQs
Here below you will find some of the most frequent questions I often get by studens or divers that are planning on buying a new dive computer.
Is Buying A Dive Computer Worth It?
A dive computer is definitely worth it for several reasons:
- it provides you with real-time information about depth, bottom time, and decompression limits, allowing you to dive safely and avoid decompression sickness.
- it tracks your dives, allowing you to analyze your performance, identify patterns, and improve your diving skills.
- it eliminates the need for dive tables and reduces the risk of errors in manual calculations.
Overall, a dive computer is a valuable tool that enhances your diving experience and safety.
Do I Need Two Dive Computers?
It is not strictly necessary to have two dive computers, but there are some benefits in doing so in special situations.
On the one hand, having a backup dive computer can provide added security in case of malfunction or failure of the primary one. This is especially important for more experienced divers or those doing technical dives, where equipment failure can have serious consequences.
Second, having two dive computers can allow you to dive more conservatively, by comparing readings and making more informed decisions.
Finally, whether or not to have two dive computers is a personal choice based on individual needs and preferences.
Air Integrated vs. Non Air Integrated Dive Computers
Air integrated and non air integrated dive computers differ in their ability to monitor a diver’s remaining air supply.
Non-air integrated dive computers rely on the diver to monitor their air supply using a separate pressure gauge. The computer calculates the remaining dive time based on depth, time, and previously entered gas settings, but does not have real-time information on how much air the diver has left in their tank.
Air integrated dive computers, on the other hand, are able to monitor a diver’s remaining air supply in real time by using a wireless transmitter attached to the first stage regulator that sends tank pressure data to the computer. This allows the dive computer to provide a more accurate estimate of remaining dive time and can help divers better manage their air consumption.
Air integrated dive computers can also provide additional features such as air time remaining calculations, warnings when air levels get low, and automatic switching to a backup air source if necessary. However, air integrated dive computers tend to be more expensive than non-air integrated models and require additional equipment and maintenance.
Ultimately, the choice between an air integrated and non air integrated dive computer comes down to personal preference and diving style. Recreational divers who dive with a single tank and are comfortable monitoring their air supply with a separate pressure gauge may prefer a non air integrated computer, while divers who want real-time air consumption data and additional features may prefer an air integrated dive computer.