Dive Computers

How to Use and Choose Dive Computers

Suunto Stinger Dive Computer

During a scuba dive, nitrogen from your breathing air dissolves into body tissues due to the increased pressure. The

deeper you dive, the faster nitrogen dissolves into your body. It’s important to keep this dissolved nitrogen within accepted limits to minimize the risk of decompression sickness. To do this, your dive computer tracks your dive depth and time. It calculates theoretical nitrogen using a decompression model and displays the time and depth limits you need to stay within.

Also known as : deco meter, decompression meter, decompression computer, scuba diving computer, dive computers with full decompression models.


Dive Computers

There are two basic styles of dive computer.

Independent – These computers are separate gauges that you wear on your wrist or as part of an instrument console.

Integrated – These computers integrate with your SPG and/or other instruments, such as an electronic compass. By also measuring your air supply, some models can estimate how much time your remaining air gives you based on your depth and how fast you’re breathing.

Required features

Easy to read display – You consult your computer constantly while diving, so choose one that makes sense to you and that you can read easily.

Choose a dive computer that has an easy to read display

Low battery warning – Once activated, a dive computer will need to run 24 hours or longer to calculate changes in dissolved nitrogen. The computer must be able to warn you if it won’t have enough power to do that. Virtually all modern computers have this feature, alerting you to change the battery before starting your dives.

Enriched air compatible – This allows you to set the computer to dive enriched air nitrox. Enriched air gives you longer dive times, all else being equal, and the setting tells the computer to track your exposure to oxygen. At one time considered an option, today diving with enriched air nitrox is so common that you’ll want to become qualified to use it shortly after becoming a PADI Open Water Diver. Virtually all modern computers have this ability.

Optional features

There are many options in dive computers. Some of these are very important for specific types of diving, whereas others are personal preference.

  • Hoseless integration – Some integrated computers receive air supply information from a transmitter on the regulator first stage. This eliminates a hose and allows you to wear an integrated model on your wrist.
  • Watch sized – Some of the newest dive computers (integrated and non integrated models) double as digital dive watches
  • Multiple gas – Aimed primarily at tec diving, you set these models for two or more different types of enriched air or even trimix (a tec diving blend of helium, oxygen and nitrogen). This allows the computer to calculate as you switch gases during the dive.
  • Audible warnings – Most computers sound an alarm if you ascend too fast or near a limit.
  • Computer download – Some computers interface with your PC so you can download your dive data. This provides detailed dive information and is a convenient way to keep a computerized dive log. You can also purchase a PADI paper log book from your local dive shop.

How to choose a dive computer

Choosing a dive computer is a matter of personal preferences and cost-versus-features.

Get your PADI Instructor or a dive professional at Easy Divers dive shop to help you. The options and choices can seem overwhelming, but your PADI pro can narrow it down very quickly by asking you a few simple questions.


  • Don’t share it and don’t turn it off. A dive computer tracks changing theoretical gas levels for each individual diver during a dive, between dives and during a second dive. Therefore, you can’t share it during the day. If you turn it off, it loses its memory of your previous dives (not good!), which means you can’t dive any more for at least 24 hours. You can’t turn off most modern computers, but changing the batteries during the middle of the day can be a problem. See the manufacturer instructions.
  • User settable alarms are awesome. It’s great to have a computer with automatic warnings, and new divers shouldn’t turn the alarms off indiscriminately. On the other hand, some warnings are annoying and unnecessary for experienced divers, so it’s nice to have the option to turn them off.

How does a dive computer work?

The dive computer performs a continuous calculation of gases in the body based on the actual dive profile. As the dive computer automatically measures depth and time, it reduces the need for the diver to carry a separate watch and depth gauge and is able to warn of excessive ascent rates and missed decompression stops.


A main differentiation between different brands of dive computers (beyond look and feel, price and obvious features (backlight, audible alarms etc)) is which algorith they use: there’s the Haldanian algorithm, Suunto’s Reduced Gradient Bubble Algorithm and a number of others with various merits, used by different manufacturers.

Debate is never ending about which algorithms provides the best results, quite frankly, nitrogen gas bubble formation in human tissue (”the bends”) seems to be a field in biology that isn’t particularly well-understood.

A key thing is that different algorithms and different dive computers ‘ implementation of those algorithms can be more or less conservative or aggressive: An “aggressive” computer gives more bottom time than a “conservative” one does, and it’s wise to understand the properties of one’s own dive computer to ensure it fits the skill and comfort level expected.


SUUNTO REDUCED GRADIENT BUBBLE MODEL | Most Advanced Dive Computers In The World Today



The Suunto RGBM is a modern algorithm for predicting both dissolved and free gas in the tissues and blood of divers. The Suunto RGBM is a significant advance on the classical Haldane models, which do not predict free gas (micro bubbles). It was developed in a co-operation between Suunto And Bruce R. Wienke BSc, MSc, PhD. The Suunto RGBM is based on both laboratory experiments and diving data, including data from DAN.Suunto RGBM adapts on-line to a variety of situations, such as:- Monitoring continuous multiday diving- Computing closely spaced repetitive diving

– Reacting to a dive deeper than the previous dive

– Adapting for rapid ascents which produce high micro-bubble (silent bubble) build-upBy adapting the decompression obligations according to the actual dive situations, Suunto RGBM improves the safety of your diving.




Suunto Advanced RGBM Micro Bubble Dive Model




Suunto of Finland, incorporates the latest research in decompression theory in a dive computer, which led to the development of the most advanced dive computers in the world today.

Updating to a new Suunto dive computer can make your diving safer, extend your bottom time, save you money (due to improved battery technology) and more convenient (due to reduced size). You can even make a fashion statement with one of Suunto’s advanced wristop computers.




There are many reasons to trade up to a Suunto computer, safety being the #1.  The most important difference from one dive computer to the next, is its decompression algorithm.  It is also the most difficult feature to explain and most costly to develop.   As a result more obvious but less important benefits are often used as the key selling feature, which leads many manufacturers to place less emphasis on this critical safety factor.

Most divers are lucky enough to never have a problem with decompression illness, however each year thousands of divers throughout the world do.  More importantly research over the last decade has shown that long term damage to soft tissue (the brain, spinal tissues and the retina) are far less likely if you use a dive computer incorporating the latest research on prevention of micro bubble build up.   Divers who dive very regularly, like instructors and professional divers are most susceptible to the long term affects of micro bubbles, but any diver that does multi day diving, for example on a vacation, will be affected by micro bubble build up.  Therefore, understanding what the SuuntoReduced Gradient Bubble Model (RGBM) can do to make your diving safer is critical to most divers.

The Suunto RGBM is a modern algorithm for predicting both dissolved and free gas in the tissues of divers performing a wide variety of maneuvers. It was developed in co-operation with SUUNTO and Bruce R Wienke (BS, MS and PhD) and is based both on laboratory experiments using highly advanced Doppler Bubble detection devises and is supported by Divers Alert Network’s (DAN) dive data, folding both in coupled synthesis for safety.

Suunto Stinger

State-of-the-art solutions for every diverSuunto Stinger is a full decompression dive computer and a beautifully constructed compact-size watch in steel or titanium.
Suunto Stinger Story
Suunto Stinger has everything a diver can ask for. It is a wristop computer with separate Air, Nitrox and Free/Gauge modes, each of which has a detailed profile memory.All the advanced features, such as safety stop countdown, adjustable profile memory sampling rate, underwater stopwatch and bookmarks, are easily accessible.In addition to having information available to you at all times, Suunto Stinger records and stores data for later analysis. You can view, compare, and analyze your diving performance through a specially designed PC interface.The technical features, combined with the PC interface developed for more graphical representation of your performance, and our Internet Community, where you can share information with other like-minded divers from around the world, make Suunto Stinger thedevice of choice for every diver and underwater explorer.
Deeper Understanding
Suunto Stinger is a highly sophisticated multi-level dive computer, in every sense of the word. It monitors and reports vital information such as your dive time, current depth, maximum depth, no-decompression time and ascent time.Suunto Stinger implements a Suunto-specific ceiling and floor feature. The decompression floor is the deepest point at which the ascent time will not increase. The decompression ceiling is the shallowest depth to which you should ascend. These depths provide the range where the diver utilizes the decompression stop morefore your dive. The clear electro-luminescent backlight is activated automatically when dive alarms are given, making the dive parameters clearly visible and legible. The system is highly energy-efficient with only minimal power consumption. The built-in dive planning function helps you plan your next dive by showing you the no-decompression time data for different depths.In the Nitrox mode, you can program Suunto Stinger for nitrox mixtures of 21% to 50% oxygen in 1% increments. You can also adjust it for oxygen partial pressure from 1.2 bar to 1.6 bar in 0.1-unit increments.Suunto Stinger gives both visual and audible alarms when the limit for oxygen partial pressure, CNS or OTU values are exceeded.For freediving enthusiasts, Suunto Stinger introduces a 1-second precision timer with selectable 2, 4, 10, 20, 30 or 60-second profile memory-sampling rates. After 5 minutes of continuous diving in the Free mode, it automatically switches to Gauge mode. In both the Free and Gauge mode you can use a run-time timer. This makes Suunto Stinger also ideal for technical and military diving.In the Air and Nitrox modes, you get a 36-diving hour profile memory with a default 20-second sampling rate setting. You can adjust the sampling rate to 10, 30 or 60 seconds through the PC interface. You can view the profile memory and long-term history data on the Suunto Stinger display.Suunto Stinger incorporates complete calendar clock functions,dual time, daily alarm and a stopwatch with elapsed time and split time measurement. If you disable all the dive modes, you can use it as a traditional dive watch.The casing is all stainless steel and the display is scratch-resistant mineral glass. The triple o-ring pushbuttons and its monocase design without a separate rear cover make Suunto Stinger virtually leakproof. The pressure rating is 20 ATM (200 m/660 ft).Suunto Stinger comes with a durable, gray elastomer strap, or optionally a solid stainless steel bracelet with polished center-links. The bezel color is silver. The top-of-the-line model is Suunto Stinger Titanium, with a solid titanium housing and bracelet.

Information in Action
Suunto Stinger is the ultimate choice for all kinds of recreational, military and other professional divers, and competitive divers such as freedivers and technical divers who do not compromise when it comes to the quality, materials and functionality of their equipment.Whether diving in familiar waters or exploring unknown oceans, safety is essential. Suunto Stinger is packedwith solutions enabling safe and responsible decisions underwater. The depth, time and decompression measurement, and the ceiling/floor feature assure that you know exactly how much time you have spend in the depths, how deep you are, when you have to surface and how fast you can do it. This way you can maximize the diving performance without jeopardizing your safety.The extensive memory and logbook functions enable you to keep track of your past dives and through them you can monitor your progress and plan your training accordingly.
Product Features
  • Air, Nitrox, Free/Gauge modes
  • Complete watch functions
  • Extensive memory functions
  • Adjustable units
  • Bookmark function
  • Suunto RGBM model


  • PC interface


Suunto Software
Suunto Dive Manager (SDM) is software that enables deeper understanding and better graphical representation of the data recorded and stored with Suunto Stinger.With SDM you can upload your dives to a PC and create a more detailed dive logbook. Here you can analyze and plan your sports activities and keep a training diary.You can download Suunto Dive Manager in the Software section.
SuuntoSports Community
SuuntoSports.com is an Internet site where you can share information with other like-minded divers from around the world. The community gives you the opportunity to share information, learn new things, exchange ideas, and pick up useful tips from people equally passionate about diving.You can also upload your data from SuuntoDive Manager to SuuntoSports.com in order to compare your performance with others, show off your wildest adventures, with travel reports and your digital photos, or simply share your diving experiences with friends or the entire community.

Suunto D4

Lightweight, easy to use, and practical Suunto D4 is all about enjoying your diving experience. Whether you’re on your well-earned annual dive holiday or honing your freediving skills, Suunto D4 keeps you informed and aware every meter of the way.
SuuntoD4 Story
Suunto D4 is a full-decompression wristop dive computer designed to put information, ease of use, and style first. Its four operating modes, dive planning and analysis functions, and compatibility with optional Suunto Dive Manager PC software make Suunto D4 a great choice for those who value functionality and ease of use.With its innovative freedive functions and dedicated freedive mode, Suunto D4 is also perfect if you’re serious about breath-hold diving. Programmed to sample depth three times a second, Suunto D4 records highly accurate data on the true depth reached. Surface time and depth alarms help you make responsible decisions both in and out of the water.In both Air and Nitrox mode, the clear, easy-to-read screen can display your current and maximum depth; current time, dive time, and decompression time; and temperature. Audible and visual depth and time alarms warn you when it’s time to start your ascent. In Nitrox mode, you can increase your time underwater by adjusting the oxygen content of your gas between 21% and 50% and adjust your PO2 limit between 0.5 and 1.6 bar.Like other advanced Suunto dive computers, Suunto D4 uses the Suunto RGBM algorithm for decompression calculations. It also allows you to choose between taking traditional safety stops or, with the Deep Stops feature activated, taking your safety stops at depth.Before diving, the no-stop-time planner helps you prepare for your dive. Enter the planned maximum depth of your dive, and Suunto D4 will tell you how long you can dive before needing a decompression stop. After diving you can instantly review all the data in the logbook. Suunto D4 is also compatible with the optional Suunto Dive manager PC software, which provides more in-depth analysis and graphical representation of all your dives.Mix and match your look with the new Suunto D4 dive computer straps. The new colorful selection of straps include blue, yellow, pink, or black – your choice when you purchase your dive computer. If you already have a Suunto D4, the straps can also be purchased as individual accessories making it easy to choose the style that suits you best.
Suunto D4 Features
  • Four operating modes: Time, Freedive, Air, and Nitrox
  • Dive planning and analysis functions
  • Compatible with optional Suunto Dive Manager PC software
  • Automatic safety stop countdown
  • Complete decompression stop data
  • Suunto Deep Stop RGBM algorithm
  • Multi step ascent rate indicator
  • Battery power indicator and warning
  • Depth display range: 0-100 m/ 0-238 ft
  • Glass face, display shield, and lightweight composite housing
  • Adjustable metric and imperial units
  • Comes with a scratch guard
  • Available with black, blue, yellow or pink straps


Check out also the Suunto D4 campaign site!


Find your bearings with the advanced, gas-switching SuuntoD6.This gas-switching, multi-mode, decompression dive computer with integrated digital compass will take your diving to the next level.
Suunto D6
Suunto D6 is an advanced wristop dive computer designed for demanding divers. The three operating modes, gas-switching functionality, integrated digital compass, and the Suunto RGBM deep stop algorithm combine to make it one of the most feature-rich and versatile dive computers available.All the information you need relating to depth, time, direction, and decompression status is now available on one clear wristop display.In addition to having mode-specific information available to you at all times, your Suunto D6 records and stores data for later analysis. You can view, compare, and analyze your diving performance through the downloadable Suunto Dive Manager PC software.
Deeper Understanding
SuuntoD6 has three dive modes: Air, Nitrox, and Gauge. The Air mode is used for diving with standard air, the Nitrox mode for one or two nitrox mixes, and the Gauge mode for use as a bottom timer.When in Nitrox mode, you can accelerate decompression by switching to a gas mix with a higher oxygen percentage. You can preset two different gas mixes (with between 21 and 99% oxygen) and set PO2 values for each individual gas. While diving, it’s quick and easy to switch between enabled gas mixes. Gas switching is only allowed for gases that lie within the chosen maximum PO2 limits. CNS and OTU values are displayed using an Oxygen Limit Fraction (OLF) bar graph.In the Gauge mode, Suunto D6 works as a bottom timer, and also provides accurate profile sampling and bookmarking functions. A dive timer with a reset function displays the dive time in minutes and seconds. This is extremely useful for timing accurate bottom times and decompression stops.The integrated digital compass can be accessed from either Time mode or Dive mode, meaning that it’s as useful on dry land as it is beneath the waves. The Suunto D6 displays a graphical representation of a compass rose. The rose displays the cardinal and half cardinal points, and the current bearing is also displayed numerically. A bearing can be locked to help you follow a selected course, and directional arrows point towards the locked bearing.
Information in Action
Suunto D6 is packed with solutions that help you make safe and responsible decisions underwater. Depth, time, and directional information, together with complete decompression-stop data, ensure that you know precisely how long you have been underwater, how deep you are, where you are, and what is your ascent speed.Suunto D6 incorporates Suunto RGBM, which allows you to choose a deep stop algorithm. This enables you to make iterative stops at depth instead of the traditional safety stop. During a decompression dive, this function allows you to make the most of your time underwater without jeopardizing your safety.In addition to its versatile dive functionality, Suunto D6 also boasts extensive memory and logbook functions that enable you to keep track of your past dives, monitor your progress and plan your training.
Product Features
  • Air, Nitrox and Gauge modes
  • Gas switching (2 mixes 21-99%)
  • Complete decompression stop data
  • Multi-step ascent rate indicator
  • Integrated digital compass
  • Extensive memory functions
  • Adjustable SuuntoRGBM model
  • Audible alarms (including maximum depth alarm)
  • Optional PC-interface
  • Metallic bracelet or black wrist strap


Suunto Dive Manager (SDM) is downloadable software that enables deeper understanding and better graphical representation of the data recorded and stored by Suunto D6.With SDM you can download your dives to a PC and create a more detailed dive logbook. You can also analyze and plan your diving activities. You can also create your own activity reports by adding photos and text to the profiles.You can download Suunto Dive Manager in the Software section >>
SuuntoSports Community
SuuntoSports.com is an Internet site where you can share information with other like-minded divers and water sports enthusiasts from around the world. The community gives you the opportunity to share information, learn new things, exchange ideas, and pick up useful tips from people equally passionate about diving.You can also upload your data from Suunto Dive Manager to SuuntoSports.com in order to compare your performance with others, show off your wildest adventures, with travel reports and your digital photos, or simply share your diving experiences with friends or the entire community.
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