Beginners Guide to Buying a Regulator


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Buying your first regulator set is a major step when purchasing your own gear. Many dive professionals and regular recreational divers say it is one of the top three most important pieces of gear you will buy and travel with. It stands beside your dive computer and mask.

READ  Beginners Guide to Buying A Dive Computer

Regulators are your lifeline while diving. We consider them the brain of your scuba kit because they link everything else together. We suggest buying the best you can afford.

Don’t be alarmed though, there is a very high minimum standard that regulators have to meet before hitting the market, so you can still get many quality budget friendly ones.

Compared to the other posts in the Beginner Guides To Buying Scuba Gear series, this one may be a bit more technical and complex.  But, we’re sure you will be able to learn a lot and impress your dive buddies with all your knowledge.

If you have questions, please contact us or leave a comment below!

Okay? Okay. Shall we…. DIVE in…? 😛

The easiest way to do this is to break down the regulator into its four main elements and then give recommendations on the types of diving environments each is best suited for.

First Stage

Primary Second Stage

Alternate Second Stage (Alternate Air Source/Octopus)


First Stage

The first stage of your regulator is the part that physically attaches to the scuba tank. Its job is to reduce the high pressure air in the tank to an intermediate pressure that is more manageable to use for the rest of your regulator set.

Connector Systems

A regulator first stage seals to a scuba tank valve by means of an O-ring. There are two different types of tank valves and thus two different types of regulators. DIN and yoke.

DIN Regulators and Tanks

DIN regulators use DIN tank valves where the O-ring sits at the end of a large, threaded opening. The regulator screws directly into. This creates a more secure connection and can handle higher pressures than the yoke setup. For this reason, DIN is popular among technical divers and cold water environments. Also very common in Europe.

Yoke Regulators and Tanks

Yoke or “A-clamp” regulators use yoke tank valves where the O-ring sits in a small groove on a more-or-less flat valve. These regulators fit over top of the valve and are held in place by tightening a screw. This is more common for recreational dive operators around the world and in North America.

Note that there are adapters and converter kits available to switch between the two.

DIN regulators can be converted to yoke regulators with an adapter, while there is no adapter that easily converts a yoke regulator to DIN. For this you would need an appropriate service kit and the help of a service technician.

Adapters are available to use a yoke regulator on a DIN tank. The use of a DIN regulator adapter on a yoke tank can get bulky and divers are more likely to bump their heads on it during a dive. If you plan to primarily dive with yoke tanks, a yoke regulator is your best bet.

Balanced vs. Unbalanced Regulators

The difference between these two is generally how much they cost and how they work when there are changes in pressure. In other words, how easy it is to breathe when you go deeper and/or have less air in your tank.

Balanced Regulators

With balanced regulators, you will not notice any changes in how easy it is to inhale from your regulator regardless of your depth and how much air you have left in your tank. These are more expensive and are preferred by most divers if they can afford it.

Unbalanced Regulators

With unbalanced regulators, you will notice that inhaling air from your regulator is slightly more difficult the deeper you go and as you have less air in your tank. This is generally not noticeable for dives up to 20m, but the difference can be felt when you dive deeper, closer to 30m, and when sharing air, which is obviously not ideal.

Most rental regulators are unbalanced and are still good safe, reliable options for a recreational diver. It’s not as if you are struggling to catch a breath, you would just notice or maybe not even notice a sliver of extra resistance with each inhale.

Piston vs. Diaphragm Regulators

The true difference between these two is how they work mechanically, which is not necessary for you to know at this time. They are both reliable and perform well in recreational diving. What you do need to know is why you would choose one over the other and that is based on the environments you intend to dive in.

Piston Regulators

Mechanically, these are more simple and have less moving parts. Piston regulators have more parts that are exposed to the environment, making them more susceptible to icing in cold water, which can cause a free-flow. They may also require more maintenance because of contaminants like silt, sediment and salt build up from poor cleaning.

Diaphragm Regulators

Diaphragm regulators are more complex mechanically compared to piston regulators. As a result of the design, these regulators are environmentally sealed, which means its moving parts are not exposed to the environment. This means there is less chance that the different parts will be affected by icing in cold water, silt, sediment and other contaminants. For this reason, if diving in cold environments, an environmentally sealed regulator is a must.


Ports are what you use to connect the rest of the regulator set up to your first stage via hoses. All regulators have at least one high pressure (HP) and about four low pressure (LP). HP ports are used for you pressure gauge. Many regulators have two, which would allow you to use a transmitter if you have an air integrated computer or a second pressure gauge. LP ports are used for your primary second stage, octopus, BCD inflator hose and drysuit hose. In our opinion, the more the merrier.


Some regulators allow the hoses to swivel while attached to the tank. This extra movement makes positioning (routing) hoses easier and would prevent a “tugging” feel in your mouth from your primary when turning your head side to side to look at all the amazing things on a dive. However, with more moving parts, means it’s a potential failure point. We personally prefer non-swivel options, but again, it all depends on what you like.

Second Stage

The second stage (demand valve) is what you will be putting in your mouth. When talking scuba, most people refer to this part as you regulator or reg, even though it is just a component of your entire regulator set.

READ Scuba Slang and Getting to Know Your Dive Gear

Your second stage consists of your primary second stage, which is what you breathe off of and your alternate second stage, rather your alternative air source/octopus.

The mechanical elements are the same for both. The job of your second stages is to take that intermediate pressure we mentioned earlier and turn it into a breathable air pressure.

The main difference between your primary second stage and alternative second stage, is that your alternative should have a longer hose and be a bright yellow colour, so that it is easy to locate.


Like the first stage, you can get an unbalanced and balanced second stage. I won’t go through the explanation again, but refer to earlier sections for a refresher if need be.


More expensive regulators have an adjustment knob that will allow a diver to adjust the inhalation effort while diving. This is useful in preventing free flows during a dive and on the surface.

Similarly, some have a dive/pre-dive lever, which again acts to prevent free flowing on the surface. It’s possible to still breathe while in pre-dive mode, you just may find the inhalation effort is a bit more.

These both help to save air.

Upstream vs. Downstream

Upstream and downstream refers to the direction of air flow through levers and valves found inside your second stages.


With downstream second stages, when you inhale, a valve opens and supplies you with air. The valve opens with the direction of airflow. These are mechanically simple and highly reliable.

When a first stage fails and pushes too much air pressure to a second stage, the downstream valve almost always stays in an open position. From your dive training, you know you can still breathe off of a free-flowing regulator as you ascend safely to the surface.


With upstream second stages, when you inhale, a valve opens against the direction of airflow. This means free-flows are much less likely. In the event the first stage fails, instead of remaining in an open position, like the downstream designs, upstream designs stay in a closed position, effectively stopping the free flow. However, this causes a build up of pressure which can lead to failure of a hose or another second stage. To offset this, upstream regulators must have an overpressure relief valve (OPV), which allows the diver to continue breathing.


While it’s important to have a comfortable mouthpiece it is not what you should focus on when first buying a regulator. You can easily change and replace them, but we’ve included a small section just for a little FYI.

Most standard mouthpieces are designed to be ergonomic, but you will have to try a few out to find one that you like. There are moldable mouthpieces available, which offer great comfort, since well, it’s made just for your mouth!

It doesn’t hurt to have a few spare mouthpieces in your save a dive kit either, along with a few extra zip ties.


A variety of instruments are used to help provide important information that you can’t get any other way during a dive. While technically speaking these instruments are not “regulators” they can attach to your first stage via a hose and console and are vital components to your scuba unit.

Submersible Pressure Gauge (SPG)

Your SPG is what tells you how much air you have left in your tank at any given time, making it indispensable. Most divers prefer analogue or electronic gauges in consoles that are attached to HP hoses. If you have a wrist mounted dive computer with an air integration feature, you can buy a transmitter and read your air pressure on your computer wirelessly.

READ 8 GREAT WHITE Reasons To Own a Dive Computer

Depth Gauge

While most divers use computers to track their depth, analogue gauges still do exist and are a good inexpensive backup option. You can fit them into a console with other instruments.


Like the depth gauge and SPG, compasses can be found in some of the higher end dive computers. If you choose a computer without a compass, you have the option to get a wrist compass, or like the depth gauge, add it to a console. Though, the nice thing about computers with an integrated compass is that you will have one less thing strapped to your wrist.

Quite often when you go to buy a regulator set, the retailer or manufacturer will already have suggestions on each of the components and can offer a packaged deal.

Of all your dive gear, regulators are definitely the most complex to wrap your head around and we congratulate you for making it this far!

And lastly, as always, dive safe and have fun!

“The best way to observe a fish is to become a fish.”

– Jacques Yves Cousteau


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