Dive Computers

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scuba diver with a dive computer on their wrist

The invention of the dive computer changed the scuba world, allowing divers to track their diving data in real time. Beginner divers regularly wonder if they should immediately purchase a dive computer and if so, which one?

Does Every Scuba Diver Need A Dive Computer?

Yes! At Scuba Girl Gear we recommend that, for safety reasons, every diver invest in a dive computer.

However, the technical answer to this question is no. Divers safely navigated dive after dive using dive tables to monitor nitrogen loading. To this day, understanding how dive tables work is an important piece of knowledge that every diver should have.

Diver computers, once a luxury, are now a common and indispensable tool that should be part of every divers kit.

How Does A Dive Computer Work?

Every dive computer works through a combination of sensors, algorithms, data recording, and display.

Monitoring Sensors

Dive computers use sensors to monitor the diver’s depth, time, and temperature. The depth sensor measures the pressure exerted by the water on the computer, which is converted into a depth reading. The time sensor records how long the diver has been underwater, and the temperature sensor measures the water temperature.

Algorithmic Calculation

The dive computer uses algorithms to calculate the nitrogen saturation of the diver’s body tissues based on the dive profile, including depth and time spent underwater. The algorithm then calculates the allowable dive time based on the diver’s current nitrogen levels and the dive profile. It uses this information to calculate decompression stops and to alert the diver when they need to ascend to a shallower depth to prevent decompression sickness.


Dive computers display important information such as current depth, dive time, remaining dive time, no-decompression limits, ascent rate, and more. The display typically consists of a digital screen that is easy to read underwater, even in low light conditions.

Recording and Storage

Dive computers can store and record data from previous dives, allowing divers to review their dive profiles and track their diving history over time. Some dive computers can also be connected to a computer or smartphone app, making it easy to upload and store dive data and analyze it in more detail.

Renting vs Buying: Is It Worth Getting A Dive Computer?

It’s always better to own your own dive computer. Here’s why:

Familiarity: Every dive computer works a little bit differently and it takes time to learn all of the commands. Knowing how to change the settings becomes second nature when you own your own computer.

Consistent Tracking of Dives: In the event that an accident occurs or the diver experiences decompression sickness, the information stored in a personal dive computer can be valuable.

Personalization: With so many models to choose from, it’s easy to get the computer features you want with a look you love!

The bottom line is that a personal dive computer increases safety. When a dive computer is rented, time is wasted on learning new commands and a dive history can be easily lost.

Independent vs Integrated Dive Computers

There are two types of dive computers, integrated and independent.

Integrated Dive Computers:

Integrated dive computers are built into a diver’s BCD or regulator system, and they work in conjunction with the scuba tank’s pressure gauge. The dive computer receives information about the amount of air remaining in the tank, which it uses to calculate how long the diver can remain underwater. Integrated dive computers also have sensors that monitor the diver’s depth, time, and ascent rate, providing real-time information to the diver.

One of the main advantages of integrated dive computers is that they eliminate the need for a separate pressure gauge, which can reduce the amount of equipment a diver needs to carry. They also provide a streamlined and ergonomic design, making them easier to use and access during the dive.

Independent Dive Computers:

Independent dive computers are standalone devices that can be worn on the wrist, commonly known as dive watch. They do not rely on the scuba tank’s pressure gauge, and they work independently to calculate the diver’s depth, time, and ascent rate. Independent dive computers can be programmed to use different algorithms to calculate decompression stops and dive limits, and they often have more advanced features than integrated computers.

One of the advantages of independent dive computers is that they are more versatile than integrated computers. They can be used with any scuba gear, allowing divers to use the same computer for multiple dives and with different scuba equipment. They are also typically more customizable and offer more features and options for advanced divers.

Many companies now offer integrated systems that work directly with a wrist-worn computer, combining these two options.

Overall, the choice between an integrated and independent dive computer depends on personal preference, diving experience, and the type of diving you plan to do. Both types of dive computers have their advantages and disadvantages, and it’s important to choose one that best suits your diving needs.

Features to Consider When Shopping for a Dive Computer

When choosing a dive computer, there are several features to consider that can greatly impact your diving experience and safety. Here are some important features to keep in mind:

Nitrox Compatibility: If you plan on diving with nitrox (enriched air), ensure the dive computer is compatible with nitrox mixes. Look for a computer that offers multiple gas mix settings and supports the appropriate oxygen percentage.

Display: Consider the display size, readability, and backlighting of the dive computer. A clear and easy-to-read display is crucial, especially in low-light or underwater conditions. Some models offer color displays or customizable screen layouts.

Algorithm and Dive Modes: Different dive computers use various algorithms to calculate decompression limits and dive profiles. Research the algorithms used and consider your diving preferences and experience level. Look for dive modes that suit your diving activities, such as recreational diving, technical diving, freediving, or gauge mode.

Audible and Visual Alarms: Look for a dive computer that provides audible and visual alarms for critical dive information, such as depth, ascent rate, decompression stops, and safety stops. These alerts help keep you aware of important parameters during the dive.

Connectivity and Data Transfer: Some dive computers offer connectivity options, allowing you to connect the device to a computer or smartphone app via Bluetooth. This lets you download and analyze dive data, track dive profiles, and log your dives. Consider if this feature is important to you for further analysis and record-keeping.

Battery Life and User-Replaceable Battery: Evaluate the battery life of the dive computer, especially if you plan on multi-day dive trips. Look for a model with long battery life or user-replaceable batteries to avoid downtime during diving.

Size and Comfort: Consider the size, weight, and overall comfort of the dive computer, especially if you plan on traveling with it. A compact and lightweight design can make a difference in terms of portability and overall diving experience.

Additional Features: Some dive computers offer extra features such as compasses, wireless air integration, digital compasses, dive planning functions, and integrated dive logbooks. Assess if these features align with your diving needs and preferences.

Remember to choose a dive computer that matches your diving skills, experience level, and the type of diving you plan to do. It’s also advisable to read reviews, seek recommendations, and consult with dive professionals to find the best dive computer for your specific needs.

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