The best scuba diving regulators 2023

By Mark 'Crowley' Russell

In the modern era of scuba diving, there really is no such thing as a ‘bad’ regulator. Some may not be suitable for diving in particular environments and others may not meet your personal tastes and preferences – but they are all built to exceptionally high standards. Your life depends on them, and there are no regulators on the market which cannot perform safely and effectively in the environment for which they are designed to operate.

There are, however, plenty of different models on the market. Choosing between them might be about brand recognition or loyalty, the type of diving you’re going to be doing, what’s available to buy in your particular location, or just simple aesthetics. This is an inexhaustive list of some of the top first- and second-stage combinations available on the market today.

‘Go warm, go cold, go deep, go anywhere’, says Apeks about its MTX-RC, which features the same freeze-resistant technology as the rest of the MTX-R range, packaged in a military-grade engineering design rated to temperatures between 1 and 55 degrees Centigrade. The overbalanced diaphragm first stage is environmentally sealed with 2 HP and 5 MP ports, 4 of which are mounted on a rotating turret for extra hose routing options. The pneumatically balanced second stage has protective bumpers around its most vulnerable spots, an integrated Venturi lever and an oversized cracking pressure control knob for easy breathing effort adjustment in cold water wearing thick gloves.

Fittings: Yoke or DINFirst Stage: Overbalanced diaphragmCold water: YesPorts: 2 HP, 5 MPSecond Stage: Pneumatically-balanced with Venturi controlWeight (first and second): N/A

Aqualung’s Helix is an evolution of its ‘Core’ range of regulators – a balanced diaphragm chrome over marine brass first stage with 2HP ports and 4MP ports arranged in a T-shape for streamlined hose positioning and reduced exhalation effort; the Helix also features Aqualung’s excellent auto closure device (ACD), which seals the regulator as it’s removed from the tank. The pneumatically balanced second stage is fitted with Aqualung’s ‘Comfo-Bite’ mouthpiece and a Venturi knob. The Helix is not environmentally sealed and unsuitable for cold water; divers looking for a cold-water regulator may want to consider the Helix Pro, priced at £495.00.

Fittings: Yoke or DINFirst Stage: Unbalanced pistonCold water: NoPorts: 2 HP, 4 MPSecond Stage: Pneumatically balanced with Venturi assistWeight (first and second): 685g (DIN), 875 (yoke)

More than 20 years after the first incarnation of Aqualung’s ‘Legend’ hit the market, Aqualung’s premium regulator model has definitely earned its name. The latest evolution, the LEGE3ND ELITE is designed around Aqualung’s tried-and-tested, environmentally sealed, overbalanced diaphragm first stage with its extremely useful Auto Closure Device (ACD). The pneumatically balanced second stage comes with a Venturi switch and adjustable breathing resistance control, plus a heat exchanger for increased freezing resistance.

Fittings: Yoke or DINFirst Stage: Overbalanced diaphragmCold water: YesPorts: 2 HP, 4 MPSecond Stage: Pneumatically-balanced, breathing resistance controlWeight (first and second): 974g (DIN), 1184g (Yoke)

The ‘Z’ in Z2 stands for the Zirconium plated over the brass body of the regulator, designed for increased corrosion resistance. The balanced piston-based first stage features Atomic’s ‘Jet Seat’, and a factory-fitted environmental seal is an optional extra. Two HP and seven LP ports are more than most regulators, with the LP ports located on a fixed cap instead of a swivelling body, allowing for hose routing choice. The balanced second stage features Atomic’s patented Automatic Flow Control for consistent breathing with low effort, and the titanium seat-saving orifice of the second stage reduces wear on the valve seat from repeated use, extending the service interval for the regulator to two years or 300 dives.

Fittings: Yoke or DINFirst Stage: Balanced pistonCold water: Optional environmental sealPorts: 2 HP, 7 LPSecond Stage: Automatic flow control with adjustment knobWeight (first and second) : 844g (DIN)

Atomic Aquatic’s most popular regulator, the chrome-plated brass body of the B2 is fairly conventional in terms of material design, with the balanced-piston first stage common to most Atomic Aquatics regulators. A factory-fitted environmental seal is optional, and the 5 LP ports are housed in a rotating end cap for easier hose routing. The lightweight all-titanium second stage comes with Atomic’s patented Automatic Flow Control and rapid adjustment knob, and a stainless steel swivel joint for the hose is fitted as standard. Atomic’s patented valve seat-saving orifice extends the service interval to two years or 300 dives with a limited lifetime warranty. Optional colour kits are also available.

Fittings: Yoke or DINFirst Stage: Balanced pistonCold water: Optional, factory fittedPorts: 2 HP, 5 MPSecond Stage: Pneumatically balanced with Automatic Flow ControlWeight (first and second): 1134g (yoke), 996g (DIN)

The SXS 62X regulator system is Mares’ latest ‘ultra-compact’ regulator – claimed by the manufacturer to be among the most compact on the market. The 62X balanced diaphragm first stage weighs in at just 535g in DIN form, and features the Mares AST (Auto Sealing Technology), a pneumatic system which prevents water entering the first stage, and Mares’ Natural Dynamic Flow Control to ensure constant air delivery at any depth. The SXS second stage has a curved bypass and larger diameter over other models for smoother, more comfortable inhalation, and its ultralight technopolymer construction brings its weight down to just 156g.

Fittings: Yoke or DINFirst Stage: Balanced diaphragmCold water: NoPorts: 2 HP, 4 LPSecond Stage: Balanced, Venturi deflectorWeight (first and second): 811g(DIN), 1028g (INT)

The Mares 28XR balanced diaphragm first stage is designed for every type of open circuit configuration, from deep tech and stage tanks to recreational and sidemount. The regulator is sealed for protection from cold and particulate matter, and features the Mares Auto Sealing Tech (AST) to prevent water entry when not in use. The barrel has two angled HP ports and 4 LP ports on a rotating turret, with a fifth vertical port at the end of the barrel. The pneumatically balanced second stage is made from ultralight technopolymer with a breathing effort adjustment knob and Miflex hose as standard.

Fittings: DIN onlyFirst Stage: Balanced diaphragmCold water: YesPorts: 2 HP, 5 LPSecond Stage: BalancedWeight (first and second): 1059g

Northern Diver’s Hydra is designed for both cold water and extreme diving conditions as well as less intensive warm water divers. The balanced diaphragm first stage is machined from a single piece of brass with internal chrome- and nickel-plated brass components, stainless steel spring and environmental seal, with 2 HP and 4 LP ports machined into the barrel. The synthetic resin second stage is highly resistant to impact and made with silicone diaphragm, valve and poppet seats and chrome-plated brass and stainless steel components.

Fittings: DIN (also available in A-clamp)First Stage: Balanced diaphragmCold water: YesPorts: 2 HP, 4 LPSecond Stage: Balanced with Venturi switchWeight (first and second): N/A

Scubapro’s MK2 has to be one of the most commonly used first stages for rental regulators across the globe – because it was inexpensive, reliable, and virtually bulletproof. The MK2 EVO is an updated version of that entry-level design but with a new external insulating system increasing freezing resistance by an average of 50 per cent over its predecessor – the only downstream piston-style first stage specifically designed to resist freezing in cold water. The new R105 second stage is based around the S620Ti with an anti-scratch front cover, dive/pre-dive switch, plus a soft, co-moulded purge button, and left or right hose routing for use on stage or pony bottles.

Fittings: Yoke or DINFirst stage: unbalanced pistonCold water: YesPorts: 1 HP, 4 LP Second stage: unbalanced, Venturi controlWeight (first and second): 1378g (INT)

Scubapro’s MK11 first stage, coupled with its all-purpose C370 second stage, offers a great deal of performance for the travelling diver, but for a significantly lower price than its classic MK25 EVO combos. Weighing in at just 490g (DIN version), the balanced diaphragm design of the MK11 is suitable for cold water, with two of the four LP ports being ‘high-flow’, delivering 15 per cent more air than the others. The air-balanced C370 second stage has been designed to be compact and lightweight, built with a rugged fibreglass reinforced nylon casing weighing just 171g.

Fittings: Yoke or DINFirst stage: Balanced diaphragmCold water: YesPorts: 2 HP, 4 LP (2 ‘high flow’)Second stage: Balanced, airflow and Venturi controlWeight (first and second): 661g (DIN)

The MK25 first stage has been a favourite of both recreational and technical divers for years, and the latest evolution is no exception. Although the balanced piston first stage is not environmentally sealed, Scubapro’s patented thermal insulating system and anti-freeze protection ensure reliability even in the most extreme water temperatures. Five high-flow low-pressure ports are mounted on a swivelling turret, with two HP ports on either side. The titanium-barrelled S620Ti is a recent upgrade to the long-standing S600 second stage, smaller and lighter but reinforced and using the same sized diaphragm, reducing the work of breathing rate by 37 per cent over the S600. User-adjustable inhalation effort knob and Venturi assist lever are standard.

Fittings: Yoke or DINFirst Stage: Balanced pistonCold water: YesPorts: 2 HP, 5 LP (high-flow)Second Stage: Diver adjustable with Venturi assistWeight (first and second): 749g (DIN)

Zeagle’s flagship F8 was given a makeover a few years ago, with more than 20 improvements in the balanced diaphragm first stage. The environmentally-sealed ambient chamber ensures the internals remain clear of water and silt, making it perfect for diving in all conditions, with the low-profile first stage barely reaching the top of the tank valve. The re-designed second stage with inhalation effort control knob features the same seat-saving orifice as found in Atomic Aquatics regulators, with a zirconium-plated inlet tube for better corrosion resistance and a new larger-area heat sink reducing the risk of seizure in cold water.

Fittings: Yoke or DINFirst Stage: Balanced diaphragmCold water: YesPorts: 2 HP, 5 MPSecond Stage: Breathing resistance knob with Venturi assistWeight: 1170g (Yoke)

Regulators are among the most complex items of kit and, as a result, come with an associated dictionary of technical terminology. The jargon can be off-putting, is not always adequately covered during training, and is sometimes used by salespeople to direct you to equipment you don’t really need. Having a basic understanding of the components prior to making a purchase is essential, especially if it’s your first, so take a deep breath – here’s the basics.

The first stage connects to the tank valve and converts the high pressure in the tank to an intermediate pressure for delivery to the second stages. Yoke – also known as A-clamp or ‘int’ – regulators fit over the tank valve and are secured with a screw clamp. DIN (Deutsche Industrie Norm) regulators screw into tank valves with a threaded opening. DIN regulators are less bulky, form a tighter seal, and can handle higher pressures, so many divers consider it to be a superior system. DIN tanks have a removable adapter which allows them to be used with yoke regulators, but DIN regulators need a separate adapter for use with ‘INT’ (International) tank valves, which do not have a threaded opening. DIN is rapidly becoming the dive industry standard, but it is not universal.

All regulators will work in warm, clear, water, but compressed gases cool as they expand (aerosol deodorants are a perfect example) and can cause unprotected regulators to freeze open when diving in cold water (10°C / 50°F or lower).

Environmental seals prevent cold water and particulate matter from entering the first stage, reducing the risk of freezing or fouling. Most recent designs also incorporate an external insulating system to help regulate the temperature.

By and large, manufacturers promoting regulators suitable for use in cold water will explicitly state they are designed as such.

Unbalanced regulators are operated by tank pressure, so breathing resistance increases very slightly as the pressure drops. They are the simplest design, least expensive, and the mainstay of recreational rental gear.

Balanced regulators are not affected by tank pressure, and deliver air at the same pressure throughout the dive. These days, all but the most basic of regulators are balanced.

Overbalanced regulators slightly increase the pressure of air delivered to the diver at depth. It’s a nice, but not essential, feature.

Piston regulators operate using a hollow metal piston opposed by a metal spring. They can be balanced or unbalanced, and cold-water diving requires that they have an environmental seal, or anti-freezing technology.

Diaphragm regulators are more complex in design, but they are all balanced, and the rubber diaphragm acts as its own environmental seal, hence they are preferred for deep and cold-water diving.

All regulators have at least one high pressure (HP) port for the pressure gauge (SPG) or air-integrated computer, and four low/medium pressure ports (LP/MP) for the second stages, BCD and drysuit inflators. Higher spec regulators may have an additional HP port and extra LP/MP ports, allowing for more flexibility in configuration.

Balanced second stages reduce the ‘cracking pressure’ of the regulator – the minimum pressure required for it to operate – providing a small reduction in breathing effort.

The Venturi effect, in which moving gas causes a reduction in surrounding pressure, is what makes regulators work – it also causes them to freeflow, especially at the surface. Most regulators have a Venturi control, often labelled dive/predive or +/-, which prevents this. Some regulators also have an airflow control which affects the cracking pressure, or how forcefully you need to inhale for air to be delivered from the regulator.

All regulators can be used with recreational nitrox up to a maximum of 40 per cent O2. Anything higher requires the use of compatible materials and specialist oxygen cleaning. EU standards require the use of tanks and regulators with a non-standard connection for anything above 21 per cent, but are not universally enforced.

The standard rubber hoses are fairly inflexible and prone to cracking through poor care and maintenance. In recent years, lighter and more flexible braided hoses have become very popular as they are easier to transport, provide better options for hose routing, and reduce jaw fatigue. Swivelling hose connectors provide similar benefits over the standard, rigid connectors. Some manufacturers are now fitting braided hoses and swivel joints as standard, but they are always available as optional extras.

Chief among your considerations is the type of environment in which you plan to dive. For tropical recreational diving, any regulator will do, but cold and deep-water diving require appropriate equipment.

Size and weight may be factors in your decision-making if you travel frequently.

Regulators require servicing and spare parts, so it’s advisable to buy from a local dive shop with a brand-certified technician, rather than buy a product from the internet which you may have to post overseas to get fixed.

The general advice is to buy the best that you can afford. For smaller budgets, the basic entry-level regulators are an option, as long as their limitations are taken into account. Spending a bit extra in the first place, however, may save you money in the long run as your dive horizons broaden.

Filed Under: Equipment, Kit Reviews Tagged With: Aqua Lung, Mares, Regulators, Scubapro