Which diving regulator

The top-mounted Venturi switch is easy to reach, although test divers were divided as to its effectiveness. Coupled with the MK25 EVO first stage, it took excellent simulator scores across all of our test rates and depths. While the second stage is on the large size, its light weight helped it take a very good score for comfort.

The balanced-diaphragm first stage of the RS is about as compact as a reg can get, although it still squeezes in four LP and two HP ports. The elliptical second stage has two sets of exhaust ports, with auxiliary exhausts located next to the mouthpiece, to reduce exhalation work.

On the simulator, the RS gave a solid performance, earning good and very good scores across our range of depths and breathing rates; testers reported similar performance in our test dives. The reg is bone dry, with testers scoring it very good for dryness in all positions. They also scored it very good for ease of clearing, though some found the purge a bit too stiff and eager.

The Venturi switch proved capable of taming free-flows, but divers found the tiny lever difficult to reach. The breathing adjustment, however, earned nothing but praise, with the large, easy-to-grasp knob clicking reassuringly as testers dialed in the perfect breathing resistance.

It showed solid performance on the simulator and took very good scores across the board for ease of breathing and dry air delivery in all positions. Test divers found it easy to purge and clear, helped by a diaphragm cover nearly as wide as the reg. But its trim dimensions and near weightless comfort made it a top contender in its category. The Prana is based on the long-serving GS, with a clear family resemblance.

But while the chunky, balanced-piston first stage and top-mounted Venturi control are still there, the Prana has benefited from the makeover. And the Prana has the same smooth breathing and lightweight comfort that we liked in the GS Test divers rated it very good in all positions for ease of breathing and dry performance.

Its compact profile and near-neutral feel in the water tied top score in its category for overall comfort. Divers found the breathing adjustment effective, but also noted that a wide-open setting was a little prone to free-flow.

But test divers also selected it as their favorite in its category. This allows the air to flow through several hoses including the one leading to your second stage. The second stage further reduces the pressure to a breathable pressure, allowing you to breathe comfortably underwater. The second stage uses a demand valve to deliver air only when you need it with each inhale.

Many second stages also include an adjustment knob that allows you to adjust the flow of air to your preference. This device helps to prevent free-flows and allows you to conserve air if desired.

With an unbalanced regulator, the deeper you dive, the more effort you exert to breathe. These are recommended for shallow dives. A balanced regulator uses environmental pressure to adjust the interstage pressure in the regulator which means the regulator breathes the same regardless of how shallow or deep you dive. The second stage has a comfortable mouthpiece attached allowing the diver to breathe from it easily. If you look at them in cutaway drawings regulators may seem technical and complicated, but all modern first and second stages are actually very sound and straightforward devices, specifically designed to be tough and trustworthy.

When you breathe in on the second stage, you create a drop in pressure inside the body of the second stage. This causes a specially designed silicone rubber diaphragm to move inward sort of like when you inhale on a plastic soda bottle and the sides move inward. The diaphragm contacts a lever attached to a small valve which rocks open, allowing air to enter the mouthpiece. If you only breathe in a little, the diaphragm only moves a little, and just a little air is released.

But if you inhale forcefully, the diaphragm and lever move farther, giving you a larger volume of air. So suffice it to say that the air available at any one time will be greater than what you could ever use in a typical diving situation. The first stage, which is located between the scuba cylinder valve and the hose feeding the second stage, is responsible for taking the high-pressure air coming out of the tank and reducing it to the psi or so intermediate pressure that the second stage needs to function properly.

One thing most modern regulators have in common is dependability. They are built to stringent quality standards and they are designed in such a way as to always provide air to the diver, as long as there is air in the scuba cylinder.

Modern regulators come in a wide variety of shapes, sizes, materials, and technologies, as well as a wide range of prices. If you've never shopped for a regulator before, you'll find there are many choices available.

We're here to help you understand the different features and benefits of the various models and styles. If you are going to do primarily the sort of diving that the typical newly certified divers usually enjoys — relaxing dives on vacation in warm water locations, and at recreational depths — you'll do fine with most regulators on the market today.

If we sell it, the diving regulator will be a high quality piece of gear that will serve you well for vacation diving for many, many years to come. So why are there so many different regulators on the market?

Generally the variety is there to answer needs generated by specific and specialised types of diving. If you're planning on traveling a lot, for instance, and you need to conserve weight and space in your baggage, it will probably interest you to know that many manufacturers offer regulators for the traveling diver that are both lighter in weight than, and pack more compactly than, your average regulator.

These light weight regulators may, for instance, replace the marine grade plated brass used in many regulator components with strong, lighter weight alternatives, such as titanium. But the vast majority of premium regulators are designed to handle one or more of three conditions.

They are designed to be used in colder water, or they are made to be used comfortably at greater depths, or they are designed to function well under high work loads — swimming against a strong current, say, or doing something strenuous like dislodging a stuck anchor or digging as part of a scientific underwater archaeology project. To understand how these high performance regulators work, you can look at differences in their basic design. It's important to know that, when it comes to performance, some of the most significant differences in regulator design are found in the first stage.

You'll hear most first stages being referred to as unbalanced or balanced, and as piston or diaphragm designs. Here's what those terms mean:. The backup can either be a second mouthpiece attached via its own hose to the first stage, or incorporated into the hose that you use to inflate and deflate your buoyancy compensator. As a general rule of thumb, your octopus should have performance characteristics similar to those of your primary second stage.

That way, if you have to go to someone's aid, they will be breathing from a regulator as good as the one they started the dive with — a good way to take some of the pressure out of a possibly stressful situation. The all-purpose category is aimed at the active diver who likes to explore a range of different environments, from shallow tropical reefs to deeper, colder waters, with both recreational and technical diving in mind.

They are often made from higher quality materials, perhaps lighter in weight, and engineered with an extra degree of precision to make the most of their performance. Many people will enjoy their diving without noticing a great deal of difference, but for those who seek to master the art of diving, those extra tweaks might become much more important. The single piece body and flexible nylon hose reduce the overall weight, with the second stage geared towards reducing jaw fatigue on long duration dives.

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.

Optional colour kits are also available. Dive Rite caters mostly to the technical market and the XT draws on the company's technical roots to provide a regulator that all divers can appreciate. The balanced piston XT1 first stage is environmentally sealed and comes with five LP ports on a swivel turret and 2 HP ports at right angles to the barrel for optimal hose routing. The Abyss 52x features an all-metal second stage, with most of the same features of the Rover series, including the air bypass tube VAD which balances the second stage for sensitive and easy breathing, regardless of depth.

The smart-looking balanced diaphragm first stage is designed for cold water diving, with the Mares NCC Natural Convection Channel increasing surface area for heat exchange. The OMS Airstream Evoque is a high-performance regulator which has been designed with the optimisation of hose routing in mind.

The overbalanced diaphragm first stage is environmentally sealed as standard with a polished stainless steel finish. The balanced second stage is amongst the best in terms of work of breathing rate, with an adjustable airflow control and Venturi switch, coupled to the first stage with a 75cm Miflex hose as standard. The MK25 first stage has been a favourite of both recreational and technical divers for years, and the latest evolution is no exception.

Five high-flow low-pressure ports are mounted on a swivelling turret, with two HP ports on either side. The titanium-barrelled STi is a recent upgrade to the long-standing S 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 S User adjustable inhalation effort knob and Venturi assist lever are standard.

The chrome plated R is a balanced diaphragm regulator with a full environmental seal and dry ambient pressure chamber, ensuring that the internals of the first stage are protected from all contaminants and cold water, with a ribbed external heat exchanger to further reduce problems associated with cold water.

The DX ICE has a balanced diaphragm first stage of forged brass with a sanded chrome finish, and an anti-ice kit to insulate it from the outside.

Two of the four LP outlets are inclined at 20 degrees and the others at 30 degrees for increased hose routing options, and a stainless-steel removable valve seat is designed to increase servicing safety and simplicity. The balanced second stage is treated for abrasion on the outside, and has airflow and Venturi controls to regulate cracking pressure and prevent freeflow. 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.