Side Vented or Front vented?

While not a serious deal breaking decision, there are some models of regulators out in the market that offer second stage exhaled gas venting from the side of the regulator instead of the front which is usually the case. Side vented regulators prevent exhaled bubbles from obstructing your view during ascents and descents offering divers a cleaner view.

Piston or Diaphragm?

The first stage of a regulator may contain either piston or diaphragm mechanisms to regulate the intake of air into the medium pressure chamber and the second stage. The Piston type contains a mechanical piston that sits atop of the air intake valve, and as the diver breathes from the second stage, the piston rises and allows air to enter the medium pressure chamber ready for the diver’s next breath.

Diaphragm type regulators are more complex and are environmentally sealed which is why they are used more for cold water divers and for divers in silty and high particle content waters.  The diaphragm is a flexible cover over the air intake valve that flexes in-ward or collapses as air is breathed in from the second stage allowing air to rush into the medium-pressure chamber of the first stage.

Piston regulators are said to have better flow rates since there is only one moving part, the piston, however performance wise most differences in flow are hardly significant enough to draw up a comparison. diaphragm regs are more suitable to diving in extreme conditions such as dirty water or cold water due to their “sealed” design.

So which one is better Piston or Diaphragm? Perhaps in the past there was good enough reason to select one over the other, but in today’s world, both types of regulators have seen extensive development and as it stands now, there is no compelling reason to select one over the other.

Un-Balanced, Balanced or Over Balanced?

These terms refer to the parts used in the first stage of regulators and mean the following-

An unbalanced regulator uses fewer parts. As a result it sacrifices a bit performance at lower tank pressures and at deeper depths. It’s mainly suitable for very basic diving. An unbalanced regulator will become harder to breathe from as depth increases and or tank pressure decreases. Usually un-balanced regulators are offered on the base models of regulator product-lines.

A balanced regulator uses more parts in the first stage of the regulator to ensure that it delivers the same amount of air at all pressures and depths. So the performance of such regulators is consistent at all times of the dive and in either shallow or deep waters.

An overbalanced diving regulator incorporates a technology that makes breathing easier as you go deeper. These type of first stage regulators is mostly seen in the top ranges.

What should you go in for? Always try and opt for a balanced regulator and an overbalanced one only if you can afford it.  A balanced reg  is all you would need to meet the needs of recreational diving as it makes breathing resistance less and therefore breathing easier. If you are in to deep diving then an overbalanced regulator will adjust to depth offering you more air the deeper you go.

Scuba Regulator Selection Guide – II was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

DIN or International A-Clamp?

One of the most basic decisions a Scuba Diver has to make while selecting a Regulator first stage is the kind of tank connection fitting it should have. Essentially there are two types of tank fittings DIN and International.

The “International” fitting is also known as “Yoke” or “A-Clamp” or sometimes simply as “Clamp”. The International fitting is older and also the most widely used type of connector for attaching the vertical tank valve to the regulator’s first stage. It resembles an uppercase “A” and has a screw on the top to tighten the valve to the tank, as well as a horizontally mounted release valve to turn the air to the first stage on or off.  While A-Clamps or International are more widely used across the world, they  cannot contain pressure greater than 232bar after which the o-ring can over pressurize which is why they are gradually being replaced by the newer safer DIN connectors.

DIN or Deutsches Institut für Normung (German Institute for Standardization) is a newer method utilizing a screw fitting to mount the first stage to the cylinder. Instead of the regulator clamping onto the outside of the cylinder valve, it screws into it. The O-ring is contained internally, well protected and the screws threads allow tank pressures of up to 300bar. DIN fittings are being more widely implemented round the world especially by technical divers.

featured above is the DIN Type Zeagle ReZort Din First Stage only

The type you opt for depends entirely on the places you dive the most. We recommend you buy a DIN regulator and an adaptor that can convert the DIN to an A-Clamp if the dive shop at your destination doesn’t support DIN. However if you have an A-Clamp type regulator and the Dive Shop only provides DIN tanks, then you have a problem. A-Clamps can be converted by dive shops to DIN but at a price.

Nitrox or Air?

While it might appear so, not all regulators are Nitrox ready, unless the manufacturer specifically states it as a Nitrox Ready Regulator. So what makes a Nitrox regulator different from an ordinary one? Well not much but To be ‘nitrox ready’ manufacturers have to ensure that the regulator and all its components are capable of handling a higher than normal O2 content, and will not react with the oxygen corroding parts or cause combustion. Nitrox regulators also need to ensure the regulator is contaminant free, and that lubricants or grease used are O2 “friendly”. EAN Regulators also have thicker O2 corrosion resistant O-rings that are specially colored green to differentiate them from the regular ones. Always check the EAN percentage of your nitrox regulator as some offer EAN 23% and others up to 40%. Titanium regulators are not suitable for use with nitrox. Nitrox regulators need to be oxygen cleaned each year to keep them contaminant free at least once annually or more frequently if contaminated with unclean air which can increase the ongoing maintenance costs.

Scuba Regulator Selection Guide – I was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

In the unlikely event of a dive computer failure during a dive and you have no backup means of calculating your decompression times, the best piece of advice is the same as for any equipment failure which is; abort the dive.

If the computer malfunctions, and you are only diving an NDL (No Decompression Limit) profile, and you know that you are well within your NDL, simply abort the dive. Even though your dive buddy may be wearing a dive computer, there is no way of being sure that your profile was the same as his. Also ensure you make your safety stop at 10ft/3m. You may use your buddies dive computer to monitor your ascent and time your safety stop if you aren’t wearing a watch.

If it was your first dive of the day and you know you were within NDL, then referencing a dive table, look-up the surface interval for the maximum pressure group (i.e. Z in the PADI RDP) and observe the maximum surface interval before planning your next dive using the Dive Table.

If you were unsure whether you were within NDL before the dive computer conked-off, then it is recommended that you do not dive again for at least 24 hours and allow your body to reset and allow all the microbubbles to dissolve.

It is always a good practice to plan your maximum bottom times using a dive table before a dive and write down the depth & times allowable on a dive slate if you do not carry a copy of the dive tables in your BCD pocket. Wearing a water-resistant or dive watch in addition to your dive computer will help a diver fall back on his dive tables in case of a computer failure, provided he remembers to turn on his stopwatch or record the entry time at the start of the dive. In the same manner an analog SPG or depth gauge with a maximum depth needle will help you keep track of how deep you went when your computer failed.

photos from flickr by: DocJelly & ChrisDag

What To Do In Case Of A Dive Computer Failure was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Wetsuit Styles
There a several choices of styles, when you go wetsuit shopping. There’s the Full wetsuit also known as the full body wetsuit with sleeves right up to the wrists and legs to the ankles. Needless to say it offers full protection and better warmth as it covers most of your body. Secondly there’s the Shorty. Shorties as the name suggests have short sleeves and end just above the knee. A good choice for warm water diving, many divers prefer shorties because it allows greater flexibility in movement underwater. They’re also a easier to put on and take of than a full length wetsuit.

Another option in style of wetsuits is the Farmer John/Jane which are two piece suits, with a sleeveless full length piece worn with a covering jacket. This style is also available in the shorty form. The question of whether one should wear a shorty wetsuit has been asked and debated constantly by divers and you can read up more of our thoughts on the subject in - To Shorties or not to Shorties?

Wetsuit Thickness
Thickness is probably the most important consideration you’ll have to make when buying a wetsuit. It’s a critical factor in keeping you warm and and toasty during a dive. The thicker the wetsuit the warmer it will keep you. Some wetsuits actually have 2 thicknesses on different parts of the wetsuit. For example a 5/3 mm wetsuit means the thickness would be 5 mm on the torso and 3 mm on the arms and legs.

While there’s no particular guide to which thickness is best in a wetsuit as it differs according to the temperature of the water and the relevant conditions, here’s a rough guide to what water temperatures and suitable wetsuit thicknesses are often recommended. But your preferences can differ depending on your cold threshold.

2 mm: Water temperatures above 85 F
3 mm: Water temperatures between 70-85 F
5 mm: Water temperatures between 60-70 F
6.5 mm: Water temperatures between 50-70 (at these temperatures the use of a drysuit can also be recommended)

Wetsuit Fit
It’s very important that your wetsuit fit perfectly for it to be effective. So trying on wetsuits before you buy any is crucial. It can be frustrating and time consuming as trying them on is not always easy but don’t skip this step or you’ll regret it for sure.

If you haven’t worn a wet suit before, you should know that if you can put it on easily it’s too big for you. Especially since you’ll be wearing your wetsuit when it’s dry on land, a sign of the right fit is, a little struggle, huffing and puffing when you put it on. Scuba diving wetsuits feel snug on you and it will probably feel that your movement are restricted, which is normal.

The wetsuit shouldn’t be too tight so that it cuts of circulation at your wrists and ankle or your can even bend your knees in them. It shouldn’t be loose either cause that will allow water to flow freely through it defeating the purpose completely. There should not be any large gaps in the underarm or crotch area. However, it may probably have a gap at the small of the back, which is ok.

No matter how time consuming it is to try on different wetsuits, it’ll be well worth all your time and effort to have a perfectly fitting wetsuit that keeps you warm during your dives. There’s nothing that can ruin a dive faster than being cold and shivering while you are underwater, so get it right when you buy one the first time.

Mares Trilastic Deluxe 5-4-3mm One Piece Wetsuit, Henderson 3-MM Titanium Hyperstretch Mens Shorty, Henderson 7mm Gold Core Neoprene Men’s Wetsuit all available at LeisurePro.com

SCUBA Gear: A Complete Wetsuit Buying Guide was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Here are a few steps to taking good care of your Scuba regulator-

1. Taking your regulator off your Scuba tank, you first want to make sure to dry the dustcap by blowing the water off with the help of the air from the tank or with a dry towel. The idea is to keep the first stage of the regulator absolutely dry, so go ahead and blow some air from your tank into the first stage as well to dry it properly before sealing it tightly with the dustcap.

2. Rinsing your regulator properly is the most important step to maintaining it. Regardless of whether you have been diving in salt water or fresh water, see that the first thing you rinse off with fresh water is the regulator if not any of your other equipment.

3. Soak your regulator in warm (not hot) water to dissolve any dried salt crystals or other deposits that may have accumulated in the interior. While the regulator is soaking it’s a good idea to slosh it around and push any buttons or work the levers underwater to loosen any stubborn particles. However, be careful not to push the purge as you don’t want water to flow through the hose and back into the interior of the first stage assembly.

4. Run a stream of fresh water through any open ports and chambers to get rid of remaining particles, if any. Take off the yoke screw and rinse both the yoke and screw threads with the running water, carefully keeping the dustcap secured over the first stage.

5. Allow your dive regulator to dry properly (not in direct sunlight to protect the rubber parts) before storing it in a cool dry place with all the hoses neatly arranged and not tangled.

6. Get your regulator professionally serviced. Most manufacturers recommend a servicing by a trained technician annually. If you use your regulator extensively or commercially, it should be serviced every six months or every 50 dives.

* Pictured above – Mares Proton 42 Metal She Dives Regulator from LeisurePro.com

Mind Your Gear: Taking Care of Your Scuba Regulator was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Visit Scuba gear on Polyvore.com for details on the gear pictured above or visit www.leisurepro.com

Mask & Snorkel: Needless to say Dive Masks are your windows to the underwater world. Keeping water out of your eyes and making your view of coral, fish, sea mammals and other life that much more clearer. Masks prove very important as they are have an air pocket in front of your face which allows you to equalize your ears while descending.  The snorkel on the other hand is not really considered a necessity but proves useful when breathing at the surface before descending, without having to use the air in your tank.

Dive Booties and Fins: Fins are to a diver exactly what a tail and fins are to a fish, a means for movement and propulsion underwater. Diving fins are important in terms of helping a diver move with ease, navigate and work again currents. When a diver moves easily and effortlessly underwater using good Scuba fins they in turn conserve more energy, thus using up less of their air supply.  Dive booties are neoprene boots worn with fins for a snug fit. (See How good dive fins can make a difference.)

Wetsuit: Wetsuits are more than just dive apparel. Their primary function is for warmth. Made from neoprene, wetsuits preserve body heat by trapping a layer of water against the skin through the material. This water warms up because of body heat and acts as an insulator. Wetsuits unlike dry suits are not good insulators against very cold water but are decent protection from minor thermo clines (changes in water temperature at different depths) and are available in different thicknesses making them suitable for diving in different water temperatures.

Tank: A Scuba tank is where the air a diver breathes is stored. A common misconception about diving is that a diving tank is filled with oxygen, which is not true. For Scuba diving, the regular air we breathe is compressed at about 3,000 psi and filled in the tank/cylinder divers use. It has the same composition of regular air which is around 78% Nitrogen, 21% Oxygen and the remaining other gases.

Buoyancy Compensator (BC)/ Buoyancy Control Device (BCD): A BCD or Buoyancy Compensator is a vest like fitted jacket to which the tank is strapped on and worn by a diver. The BC is connected via a hose to the tank and has air pockets which can be inflated and deflated with a push of a button allowing you to control your depth in the water and also compensating the weight of all the equipment including the tank used by a diver. Another way of inflating a BCD is manually as they have a mouth piece you can blow into.

Weight Belt: People are positively buoyant and therefore need weights to help them descend and stay underwater while diving. Typically weights are added to a belt that goes around your waist or in some cases weights can be put into your BCD pockets. The amount of weight needed differs from person to person depending on body fat and a person’s natural buoyancy.

Regulator: A Scuba regulator is what allows you to breathe underwater. The regulator attaches to the top of the tank and then has a hose connecting it to a mouthpiece allowing you to inhale air underwater. The main function of the diving regulator is that is reduces the pressure of the air that is stored in the tank from 3,000 psi to a safer level and more breathable 140 psi. (See How a Scuba diving regulator works.)

Alternate air source: Your alternate air source is a spare regulator used incase your primary regulator for some reason fails or if you need to share air with your dive buddy if he/she runs out.

Pressure Gauge: Also connected to your tank your pressure gauge indicates how much are is left in your tank during a dive. This gauge is also normally accompanied with a depth gauge on the same console. Sometimes a compass and dive computer can be added to the console.

Dive Computer: All dive computers tell you 4 basic things- Your current depth, your maximum depth during the dive, length of time underwater and how much longer you can stay safely underwater at any particular depth. Depending on the model of computer, it can also tell you much more information and have a lot of different features.

Basic Scuba Gear and Equipment Guide for Beginners was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

If  you just starting out Scuba Diving or are a recreational diver looking for a value for money dive computer then look no further! We at Aquaviews have compiled a quick list of 5 dive computers available for under $250 all available at LeisurePro.

Mares Nemo Sport Dive Computer Watch Black – Price $248.95

The Mares Nemo Sport Dive Computer tops my list as the best dive computer available for under $250. Supporting both Air and Nitrox diving, the Mares Nemo computer is lightweight, durable and compact. The Nemo fully functions as a watch with alarm clock function and dual time zones. Most remarkable feature of the Nemo aside from its ease of use, is the provision for user-replaceable batteries, which means you don’t have to ship it off to the company store for new batteries. The Nemo uses the RGBM Mares-Wienke Algorithm, to reduce risks associated with the formation of micro-bubbles. The inclusion of Deep Stops (decompression stops at greater depths) and an ascent rate readout, both analog and digital, make dives as safe as possible. Extremely simple and intuitive. Features easy access to all functions, both as a watch and as a dive computer.

Pros
+ Measures water temperatures
+ Logs 50 dives in memory
+ Has a Backlight
+Air and Nitrox
+ Freediving Mode

Cons
- No Compass
- No User replaceable batteries
- Complicated features

Suunto “Gekko”  – Price: $224.95

The Suunto Gekko is an ideal choice for sports divers who do not require a PC interface or simulation features. It can be used with both air and Nitrox and is designed to give the specifics of any diving situation, including decompression, at a glance. Both ascent rate and available no-decompression time are displayed graphically with clear, color-coded indicators. Visual and audible alarms are given when necessary. Maximum depth and dive time alarms can be enabled. The Gekko uses the Suunto RGBM decompression model and has a user-replaceable battery and user-adjustable metric/imperial units. The extensive logbook memory stores up to 50 hours of dive profiles and logbook data, including dive start time and date, dive time, maximum depth attained, and temperature at maximum depth. In addition, the dive history keeps track of up to 999 dives and 999 dive hours, as well as the maximum depth ever reached.

Pros
+ Easy To Operate
+ 50 hour dive memory and logbook.
+ User replaceable battery.

Cons
- No Compass
- No backlight

Oceanic “Veo 100″ Wrist Dive Computer –Price $ 194.95

The Veo 100 is an economical and easy to use wrist mounted computer with state of the art features. All of its functions are easily accessed by pressing just one button. Compact and lightweight, the Veo 100 is a breeze to pack and carry anywhere.  The Veo offers large, easy to read alphanumeric displays and color coded graphs where green means “go”, yellow means “caution” and red means “stop”. The computer can be turned on before your dive, but if you forget to do this, it turns itself on underwater. The batteries have a lifetime of 300 hours and are user replaceable at any time without the loss of data. Depth rated for 330 feet, the Veo 100 adjusts automatically for altitude and salt or fresh water.
The Veo 100 lets you choose as many as three main dive mode displays and stores data from 12 dives. Since logged dives are time stamped, finding a particular dive is easy.

Pros
+ Easy to operate
+ Easy to Read
+ Temperature Display
+ Console mountable

Cons
- No Nitrox Support
- No audible alarms
- No Backlight
- No PC Support

Aeris XR-1 Wrist Computer – Price $149.95

The AERIS XR-1 is an ideal, user-friendly diving computer for those who prefer wrist-mounted computer gear. The XR-1′s enlarged digits, easy-to-read icons, and split screen take the guesswork out of reading your dive computer. Also, the XR-1 allows you to decide what information displays; now you can customize the display to include only the things you want to keep an eye on during your dives.  The Aeris allows user replaceable battery changes, and approximately 300hrs of battery life per set. The only drawback is the absence of a backlight on the dial which would make it easier to read.

Pros
+ Temperature Display
+ User replaceable batteries
+ Performs automatically adjusts for altitude changes

Cons
- No Backlight
- No Nitrox
- Logs only 12 dives

Genesis “Resource Pro” Computer Module – Price $194.95

The Genesis Resource Pro is the only computer on the list that isn’t a wrist dive computer, but a console module mounted one.  Providing a maximum depth of 250ft, the Resource Pro has an easy to read large display and features visual alarms as well. The computer can be manually activated or water activated and can log up to 50 dives. The only drawback is regarding the rather poor battery life compared to the above, which can be overlooked with the fact that the computer also allows for user replacement of the battery. For those who want a wrist mounted computer, a wrist mount can be purchased as an accessory for less than $20 making it especially popular with recreational divers. The Genesis Resource Pro is truly value for money.

Pros
+ lightweight
+ Log: 50 most recent dives.
+ Consumer replaceable batteries.

Cons
- No Nitrox
- Short Battery Life

Photos: Daniel, Daniel Kwok, Leisure Pro.com

See more Dive Computers available at LeisurePro.com

5 Dive Computers for Under $250 was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Balanced Vs Unbalanced Vs Overbalanced Regulators
These terms refer to the parts used in the first stage of regulators and mean the following-
-          An unbalanced regulator uses fewer parts. As a result it sacrifices a bit performance at lower tank pressures and at deeper depths. It’s mainly suitable for very basic diving.
-          A balanced regulator uses more parts in the first stage of the regulator to ensure that it delivers the same amount of air at all pressures and depths. So the performance of such regulators is consistent at all times of the dive and in either shallow or deep waters.
-          An overbalanced diving regulator incorporates a technology that makes breathing easier as you go deeper. These type of first stage regulators is mostly seen in the top ranges.

Piston Vs Diaphragm Regulators
Again in the first stage of regulators for the same function of lowering pressure from the tank, a diaphragm or piston is used. Both types perform more or less the same and both perfectly great and very reliable for recreational diving. The only difference between the two is-
-          Piston regulators are basic and simple have a slight performance edge at depths. They cannot be overbalanced.
-          Diaphragm regulators are a little more resistant to cold and water with particles like silt, sand or salt as the internal parts aren’t directly exposed to the water like in the piston type.
The differences are negligible in both types and aren’t really a serious consideration when choosing a diving regulator.

DIN Vs Yoke/ A-Clamp
These are the two different types of fitting for attaching your scuba diving regulator to your tank.
-          DIN which stands for Deutsches Institut für Normung is a fitting that screws directly into the tank. It’s more commonly used in Europe.
-          A Yoke fitting screws over the tank. It’s also called A-clamp and is most popular in the UK.
Both types of fittings are reliable and used commonly. If you choose to go with a DIN fitting you can buy a DIN to yoke style converter which will give you the flexibility of using either one whichever is more convenient at the time.

High Pressure and Low Pressure Ports
The first stage of scuba diving regulators has ports which connect other parts of the regulator like an octopus, inflator hose, pressure gauges, dive computers (sometimes wireless) and any extras. These can be high pressure or low pressure ports.
-          Low pressure ports are used to connect only low pressure items, via a hose, such as the second your alternate breathing source and your Buoyancy Compensator inflator.
-          The high pressure ports connect high pressure items such as your analog pressure gauge or dive computer.
It is useful to choose a regulator with multiple high pressure ports should you wish to add on any extras in the future.

Nitrox Compatible
Another aspect to consider when buying a Scuba regulator is whether it is Nitrox compatible should you choose to dive Nitrox later.

For more on How to Choose a Diving Regulator, here’s a video demonstration by one of our professionals at Leisurepro showing you the differences and types of regulators you just read about-

*pictured above- Mares Abyss 22 Extreme Regulator

SCUBA Gear: How to Choose a Diving Regulator was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

If you thought dive fins were only big plastic blades to strap on your feet, then you haven’t experienced a great pair of Scuba Fins yet. In SCUBA Diving, Fins play an integral role in propelling a diver forward, the diver’s agility under water and not to mention is critical for diving in currents. Taking all this into consideration and giving due importance to fins, Mares introduced Fins made of two different materials, with a water channeling system and with the O.P.B. (Optimized Pivoting Blade) system to maximize thrust.

The OPB System (Optimized Pivoting Blade) patented by Mares, ensures that the blade is always at an optimal angle during both the upward and downward strokes, thus considerably increasing efficiency. In contrast to traditional fins the OPB System is said to ensure the divers muscular effort to be translated into effective thrust in the direction of motion. The OPB System also makes it possible to virtually eliminate the dead angles (minimizing fatigue) that normally exist with traditional style fins. So confident with the technology and design of the new Mares Volo fins boasts of 8 patents.

And the reviews say:
“They’re like mercury’s winged boots… Everything I want-power, agility, speed. I just love these fins.” -Scuba Lab
“Truly the best of both the Volo and the Quattro, combining pivoting blade efficiency and channel thrust power.” – Sport Diver Magazine

*Pictured above: Mares Volo Race Full Foot Fins (left) & Mares “Volo Power” Open Heel Fins (right) available at LeisurePro.com

SCUBA Gear: Mares Volo Fins with Optimized Pivoting Blades was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

The most important and key piece of any divers equipment is the Regulator. A diving regulator is the lifeline between the diver and his air source (Scuba tank) underwater. This breathing apparatus that is the regulator and tank, are the only means of a person breathing underwater. In other words they are what makes SCUBA Diving (which stands for Self Contained Underwater Breathing Apparatus) possible at all.

The primary function of a scuba regulator is to decrease the high pressure under which the air in your dive tank is stored, to a much more reduced and safer pressure level which you can breathe at any depth. For this purpose Scuba diving regulators work in two stages-

First stage: Air is compressed and stored in the tank under high pressure, about 3000psi. In order to reduce this pressure, the first stage is a valve or piston that lowers the pressure to about 140psi to let air into the hose. The valve opens to let some air into the hose and then closes again. A regulator compensates the pressure as it decreases in the tank when air is used and as the diver changes depth which causes change the ambient water pressure.

Second stage: The second stage of a scuba regulator is basically the part that goes in your mouth and delivers air upon demand. It contains a mechanism that reduces the intermediate pressure in the hose coming from the first stage to the surrounding water pressure making it comfortable and easy to breathe. Like in the first stage, the second stage also contains a piston or diaphragm construction which starts and stops the airflow. The mouthpiece, an exhaust valve and an emergency purge valve/button are all parts of the second stage. The exhaust valve lets the air escape into the water when you exhale. It is a one way valve and does not let water in. When the purge button is pushed, it forces air to flow continuously into the second stage chamber forcing any water out of the mouthpiece through the exhaust valve.

Diving regulators also come in different types using slightly different mechanisms. They can be balanced or unbalanced, piston or diaphragm and use a yoke or DIN clamp we take a look at these terms and regulators in ‘How to Choose a Diving Regulator’.

How a Scuba Diving Regulator Works was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World