A scuba regulator is one of the most essential pieces of diving gear. After all, without a regulator, we would not be able to breathe compressed air at depth and our diving would be limited to breath-hold or free diving.
Some of the most frequent questions I get from newly certified divers are “what is the best scuba regulator?” or “what regulator should I buy?”.
In this post I will cover all the details that will help you choose your new scuba regulator based on your dive profile.
Table of Contents
- Choosing the Best Scuba Regulator
- How Does A Scuba Regulator Work?
- Piston Vs. Diaphragm First Stage
- Balanced Vs. Unbalanced First Stage
- Warm Vs. Cold Water Scuba Regulators
- Other factors to look for when buying a scuba regulator
- Where should I buy my scuba regulator?
- Conclusions
- Scuba Diving Regulators FAQs
How to Choose the Best Scuba Regulator
In a nutshell, when choosing a scuba regulator, you should consider:
- Diving conditions: will you be diving mostly in cold or warm water?
- Dive profile: will you be diving only within recreational depth limits?
- Where to buy: are you planning to buy your scuba regulator online or at your local dive shop?
As you might expect, the best scuba diving regulator is the one that can be used in different diving conditions (warm vs. cold water), that can best accomodate your dive profile (recreational vs. technical diving), and that can easily be serviced and inspected by your local dive shop.
This last element might sound surprising, but you should consider that if you cannot have your regulator serviced easily, you will need to add shipping costs to the annual servicing costs.
Before looking at the elements you should consider when buying a scuba regulator, let’s take a quick look at how a regulator actually works. This will help you understand the price differences among different scuba regulators, and which regulator best suits your needs.
How Does A Scuba Regulator Work?
The piece of equipment that we commonly call “scuba regulator” is actually made of three main elements. A first stage (the metal part that is connected to the scuba tank either via a din screw or a joke screw), a low pressure hose, and a second stage (the part of the regulator you put in your mouth).
Actually, scuba regulators feature two pressure hoses and two second stages. A primary second stage and a safety one, often called “octopus”.
The primary function of a scuba regulator is to reduce the pressure of the compressed gas in your scuba cylinder, making it breathable without effort at different depths. This function is mostly done by the first stage.
The first stage reduces the tank pressure to intermadiate pressure. The second stage instead reduces the intermediate air pressure to ambient pressure.
A good scuba regulator will make breathing underwater effortless, irrespective of depth and water conditions.
The key player in reducing your breathing effort is the regulator’s first stage, which can be either piston-style or diaphragm style.
Piston Vs. Diaphragm First Stage
Piston and diaphragm first stages work in a similar manner. They both have a high and an intermediate pressure chamber which help reducing the pressure of the gas in your scuba cylinder to a level that is breathable through the second stage.
In a nutshell, when you inhale from your regulator’s second stage, pressure in the first stage’s intermediate pressure chamber is reduced. The force of a bias spring combined with the force of the ambient water pressure push inward on either a diaphragm or the base of a piston head, creating an opening between the intermediate and high pressure chambers.
The breathing gas flows form the high pressure chamber to the intermediate pressure chamber and subsequently to your second stage.
When you stop inhaling, pressure in the intermediate chamber increases until it is higher than the pressure of the bias spring and water pressure so that it closes the gas valve. This is what actually prevents your regulator from freeflowing.
Although piston and diaphragm regulators work in a similar manner, they have one fundamental difference. Piston regulators feature a higher exposure to environmental conditions and as such they are more suceptible to contaminants affecting their performance.
A piston first stage is more susceptible to freezing, free flowing, and has possibly higher maintainance costs than a diaphragm regulator (which is usually environmentally sealed).
Balanced Vs. Unbalanced First Stage
Scuba regulators can be either balanced or unbalanced. A balanced regulator is designed so that the cylinder pressure does not impact the operation of the valve. Consequently, a balanced regulator ensures a consistent breathing effort, irrespectively of your depth or tank pressure.
All diaphragm regulators currently on the market are balanced.
Contrarily to balanced regulators, unbalanced ones require a greater breathing effort at higher depths or lower cylinder pressure.
Warm Vs. Cold Water Scuba Regulators
As we saw in the previous paragraphs, scuba regulators can have either a piston or diaphragm first stage and can be either balanced or unbalanced.
Although they work substantially in the same way, you need to take into account that different water conditions may impact the proper functioning of your scuba regulator.
Whenever I am asked which is the best scuba regulator, my reply is that there is no best brand or single product.
Rather, the best scuba regulator is the one that can most easily accomodate different diving conditions and that can therefore always be used both in warm and cold water diving. Ideally, the best scuba regulator can also accomodate different dive profiles, from recreational to technical diving.
With such specifications in mind, the best scuba regulators have a diaphragm, balanced first stage which is less likely to freeze or free flow if you are diving in cold water.
That said these kind of regulators are also among the most expensive, and if you are certain that you will be diving mostly in warm water not deeper than recreational diving depths, you might also want to buy a piston regulator (usually cheaper).
Other factors to look for when buying a scuba regulator
Irrespectively of whether you choose to buy a piston or diaphragm, balanced or unbalanced regulator, there are other options you should take into account when buying a scuba regulator.
Remember that depending on the type of diving you will be doing, the best scuba regulators might differ. When it come to tek diving for example, the best scuba regulators are usually not the newest products.
First stage: choosing the right amount of ports
First stages have several ports to which you can connect both low and high pressure hoses. As a minimum first stages have a single high pressure port which is used to connect the SPG, and three low pressure ports to which you can connect your primary and emergency second stages, as well as your inflator hose.
I recommend to opt for a first stage that has two high pressure ports and four or even five low pressure ports. The second high pressure port will be particularly useful in case you will buy a scuba diving computer that has a transmitter to check your cylinder pressure.
Remember that even if you have an electronic transmitter, you should always have an analogue pressure gauge as a backup.
The fourth low pressure port is instead useful in case you decide to dive in cold water and need an additional port to connect your dry suit inflator hose.
First stage: swivel turret vs. non swivel
Some first stages have a rotating part (called swivel turret) to which you can connect at least one high pressure and one low pressure hose. I find this particularly useful as it adds additional flexibility to your regulator setup.
For example if you connect your pressure gauge to the swivel turret, whenever you will take your pressure gauge to check out the remaining amount of pressure in your cylinder, you will put less strain on your scuba regulator setup.
Usually first stages that have a swivel turret tend to be more expensive than the ones without swiveling part.
Second Stage
When it comes to second stages, you will have several options to choose from, irrespectively of whether they are piston or diaphragm.
For example, if you are planning to dive mostly on holidays, you might want to opt for a compact second stage that will take up less space (and weight) in your luggage.
If instead you would like to have additional control over the ease of breathing, you might want to purcahse a scuba diving regulator with a venturi valve and rotator knob. If you are wondering what those elements are, check out my post Scuba Diving Regulator 101: Venturi Lever and Rotator Knob.
An additional factor you might want to consider is whether you would like to have two second stages or one second stage and an octopus. Although in most cases an octopus is identycal to a regular second stage (it is simply marked with a different colour), in other cases the octopus is an older model of a second stage. The second option is definitely cheaper although I personally do not prefer it.
Where should I buy my scuba regulator?
As for most of the scuba diving equipment, scuba regulators can be bought either online or at your local dive shop.
Each of the options has both pros and cons. For example, although your local dive shop might not have the brand you are looking for it might still be able to service it.
If you plan to buy your regulator online, you might find some convenient offers such as black friday deals or sales that your local dive shop might not be able to offer.
Irrespective of whether you plan to buy your regulator online or at a physical shop, there is only one situation that you definitely want to avoid: make sure you buy a regulator that your local dive shop is able to service.
If you fail to do so, you will need to add to your annual servicing costs, also the shipping costs to an authorized dealer.
Conclusions
When choosing a dive regulator, in most cases there is no one-size-fits all solution. Scuba diving regulators are in fact made for different diving conditions as well as for different dives’ profiles.
For example, if you will mostly dive in warm water, buying a scuba regulator that is made for cold water diving is a waste of money.
On the other hand, if you buy a regulator that is made to withstand cold water conditions, you will be able to use it in warm water as well.
In short, before looking for the “best scuba regulators”, you will need to have a good overview of your diving profile.
In the following paragraphs, I will cover all the characteristics that the best scuba diving regulators should have based on different divers profile.
Diver Profile 1: Recreational (holiday) diver
If you are planning to dive within recreational diving limits mostly in warm water, the best scuba regulator is definitely a lightweight regulator such as the Apeks flight regulator set.
Additional features you should be looking for:
- Overall composition: single first stage with either DIN or Yoke valves, one primary second stage and one octopus.
- Minimum Water Temperature: 50 °F or 10 °C.
- First stage should be diaphragm and balanced.
- Examples: Apeks flight regulator set, Mares SxS 62S regulator set, Scubapro MK17 MK17 EVO/C370/R095 Octo Dive Regulator System.
Diver Profile 2: Recreational (local and holiday) diver
If you are planning to dive within recreational diving limits, both locally and on holidays in warm and cold water you will want to have a regulator that is able to withstand temperatures below 50 °F or 10 °C.
Additional features you should be looking for:
- Overall composition: single first stage with either DIN or Yoke valves, one primary second stage and one octopus.
- Minimum Water Temperature: 35 °F or 2 °C.
- First stage should be diaphragm and balanced.
- Examples: ATLAS ADJ 62X, Scubapro MK25 Evo, Apeks XTX 50.
Note that in this case, depending on the proportion of cold water dives, you might want to consider purchasing two separate first stages to have a minimum of redundancy in case one of the two first stages freezes or in case on of the second stages starts freeflowing.
Diver Profile 3: Recreational (cold water) diver
If you are planning to dive within recreational diving limits mostly in cold water you will want to have a regulator that is able to withstand temperatures below 41 °F or 5 °C. This will minimize the risk of freeflow and freezing even in colder temperatures.
Additional features you should be looking for:
- Overall composition: Double first stages with DIN Valves preferred. Each first stage should have an independently connected second stage. This ensures that in case of freeflow you can shut down entirely one of the two first stages. Ideally no octopus, but secondary second stage that will function as octopus.
- Minimum Water Temperature: 35 °F or 2 °C.
- First stage should be diaphragm and balanced.
- Examples: Scubapro MK25 Evo, Apeks XTX 50, Apeks XTX 200, Hollis 200lx DCX.
Diver Profile 4: Technical diver
If you are planning to do some or mostly technical diving, the equipment needed is similar to the cold water one. The configurationchanges though, and I will cover it in a separate post.
When purchasing technical diving gear, it is essential to buy products that have been in the market for a long time and with a low track record of defaults or incidents. A good example is the Apekx XTX 50 regulator.
The best scuba regulators for technical diving are not necessarily the most expensive or newest ones, but the most widely tested ones.
Scuba Diving Regulators FAQs
What regulators do Navy divers use?
Depending on the country they are from, Navy Divers use different brands. US Navy Seals in mostly use rebreathers (LAR V Draeger) rather that a normal open circuit configuration.
Among all the regulators reported to be used by different Navy Units around the world you can find the following.
- Poseidon Xstream
- Mares Abyss 22 Navy II
- Tecline Military Line
- Apeks MTX Black Line
How much should I spend on a scuba regulator?
As you might expect, scuba regulators differ in prices based on different configurations. You can purchase a good set for recreational diving for as little as 200$, whereas a technical diving set will most likely be in the 1000$-1200$ price range.
Regulators for cold water diving are usually more expensive than regulators that are only fit for warm water diving.
Which is better piston or diaphragm regulator?
A piston regulator is more exposed to environmental conditions than a diaphragm one. Consequently, a piston regulator will need more frequent servicing, and is more likely to free flow or freeze in case of cold water diving.
What is the difference between a second stage and an octopus?
A scuba diving second stage and an octopus are substantially the same piece of gear. Contrary to the primary second stage (used by a diver to breathe from), the octopus is used in case of emergecy to supply spair air to a diver that is out of air.
A scuba diving octopus is often referred to as “emergency second stage”, “octo”, “alternate air source”, “safe second”, or “backup”.
Why do divers have 2 regulators?
Divers have two regulators, or two second stages, so that they can supply air to a buddy or diver that is running out of air during a dive.
In some cases, particularly in cold water diving, scuba divers have two separate first stages and two separate second stages. this allows them to have full redundancy in case one of the first stages freezes or in case one of the second stages starts free flowing.
How long do scuba regulators last?
Scuba regulators do not have a limited life, provided they are regularly serviced according to the manufacturer’s specifications, and provided that they are treated with care, particularly when travelling.
