Do You Really Need Your Own Dive Computer?

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After a diver has achieved their open water rating, the excitement for the sport kicks into full gear — What’s the next class to take? Where should I dive next? What gear should I buy?  

These questions, along with many others, often pop up for a new diver. Generally, dive professionals will recommend that the first order of business is to begin investing in some of your own scuba gear. What’s so important about owning your own gear?

Well, the answer is the same as the answer for many other questions about scuba diving — safety and comfort.

So, Do You Really Need to Own Your Own Dive Computer?

You need your own dive computer. Safety and comfort are of utmost importance in every corner of scuba diving. When speaking about dive gear, safety is a necessity, and comfort adds to the fun (and–you guessed it–the safety).

shearwater teric computer after a dive
The Shearwater Teric Wrist Dive computer – One of the best options in the market.

The single most important piece of safety gear that a diver can have on them at all times is a dive computer.

While it was once viewed as a luxury item, a dive computer is now a necessary piece of scuba gear.

Entry level dive courses no longer require students to learn the dive tables, which is what was historically used to monitor your nitrogen loading from a dive.

This means that the majority of you scuba students reading this article have no idea how to manually calculate your residual nitrogen, so you rely on the readings of a dive computer to keep you safe from decompression sickness (DCS). 

For divers, a small break in focus or a seemingly minor lapse in attention to safety can result in a major injury or even a fatality.

Because of this, safety is held in very high regard compared to other sports; there is no reason a diver shouldn’t want to take every precaution to keep themselves safe on a dive, and a dive computer is the most important safety item (after good judgement).

But why do I need my own? Can’t I just rent one, or look at my buddy’s?

mares and teric dive computers

Put simply, a dive computer tracks your personal exposure to breathing gases in relation to your exact depth at regular intervals, calculating how much longer you could remain at your current depth without exceeding the safe level of nitrogen in your tissues (it tracks your no decompression limit). 

Why you shouldn’t share your buddy’s computer

Relying on your dive buddy’s computer, or sharing one with your buddy, can be very dangerous.

Although it may seem like an easy way to save money, by choosing not to carry your own dive computer, you are putting yourself at unnecessary risk. 

Although the aim is to stay with your buddy throughout your dive, there is no possible way that you remain at the exact depth as your buddy for the dive’s entirety (there is also no guarantee you won’t get accidentally separated).

It is common for one buddy to drift down to the sea floor if they see something interesting while the other continues slowly along the reef, or for one buddy to hover a few feet above the other to conserve air.

These differences in depth may seem minor, but they make all the difference in how your computer measures your residual nitrogen content. 

Additionally, it’s not uncommon for one diver to have to skip a dive because of surprise gear problems, ear soreness, chill, or simple fatigue.

If that diver is the owner of the computer, you now have no dive computer for your next dive, and have to sit out, yourself. You can’t use different computers for subsequent dives, because new computers won’t have your residual nitrogen taken into account in their algorithms. 

Why you should invest in your own instead of renting

diving computer at a safety stop shearwater teric

This answer is simple — convenience and comfort! If you purchase your own computer, you will know how it works every time, and won’t have to waste any time on your scuba adventure learning how to use a new brand or model of computer.

When you don’t have to worry about learning new gear, your confidence on a dive is better, meaning you’ll have a safer dive that’s more focused on fun. 

While more and more shops are beginning to offer dive computer rentals, it is also possible that the shop you rent gear from while traveling will not offer a rental dive computer (or will charge a lot for it). If you bring your personal computer along, that will never be a worry, and will save you money in the long run.

Additional perks of a dive computer

If buying a dive computer for your safety isn’t enough to convince you, the other perks of owning one will! 


The dive tables are a useful, but very conservative way to dive. While remaining conservative is of utmost importance in scuba diving, the tables are overly so to make up for the fact that they are unable to adjust their equations to your depth as you dive.

Dive computers, on the other hand, dive with you and are continuously updating their math to reflect your actual dive profile. 

This means that your residual nitrogen can be tracked more accurately to reflect your true depth instead of the projected depth a diver uses with the dive tables.

This method is even safer, as it doesn’t rely on a diver keeping to a projected profile that is not always possible once they are underwater.

It also tracks your exact surface interval, accounting for precise nitrogen offloading between dives.

The accuracy is actually a more conservative way to track your nitrogen loading because it reflects your true profile above and below the surface.

Dive Log

56 minute dive log on the shearwater cloud dive log software
Most brands have their own apps & softwares where you can export and review your dives in detail, this is a Dive with Rudy’s Teric wrist dive computer on their Shearwater cloud software

Logging dives can be the bane of the average divers existence, but remains the most accurate way to track the skills and gear needs of a new diver.

A dive computer assists in this tedious task, as it tracks and stores all of your dive profile information for you — max depth, water temperature, bottom time, and any safety breaches that occurred on your dive.

With this stored information, you can simply look at your computer after a day of diving to record your dive log instead of trying to recall all the details by memory.

With some computers, you can even hook up your computer to a laptop and download all of the log information. 

Other Handy Features

Depending on the level of dive computer you invest in, you can also find tons of other awesome features on your dive computer.

From no fly time tracking, digital compasses, and gas mixture possibilities, to features that track your dive profile and show the data in useful graphs on pretty color screens, the variety in dive computers is vast and technically satisfying.

Essentially, dive computers are not only necessary for safety, but they are awesome tools and amazingly fun to use to enhance your dive experience! 

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