The regulator is a critical piece of scuba diving equipment. It regulates the pressure of the compressed gas delivered to the diver from the cylinder. A reg set is made up of five parts:

First Stage

This connects the other components of the reg set to the gas supply (cylinder). It takes the high-pressure gas released from the cylinder and, via ports, delivers it at an intermediate pressure to the second stage and buoyancy control device. It also allows high pressure directly into the submersible pressure gauge (SPG) from a high-pressure port.

The first stage is connected to the cylinder via a ‘DIN’ or ‘yoke’ fitting. Either of these are fine when choosing a regulator for recreational diving but a DIN fitting can withstand more pressure, so is generally favoured when you get into the realms of technical diving. It is wise to purchase an adapter with your reg set because one style of fitting may be more common than the other, depending on where you dive in the world, e.g., you’re more likely to rent yoke cylinders in the Caribbean.

Reg sets are built for different dive environments, so make sure you purchase a set compatible with cold water diving, if necessary, to prevent it icing over and malfunctioning.

Second Stage (Primary & Alternate)

These two pieces of the reg set are identical, but usually the alternate second stage is brightly coloured and on a slightly longer hose because it is only used in an emergency if the primary fails, or your dive buddy needs it.

Pressurised gas travels from the first stage, down the hose, to the second stage where the it's delivered to the diver at ambient pressure via the mouth piece. The mechanism itself on a standard second stage is called a demand valve open circuit. The air is delivered when the diver breaths in, but rather than recycling through the system, the exhaled gas expels through an exhaust valve into the water.

Features of a second stage include a purge button, which if depressed forces gas through the circuit, aimed at clearing water that gets into it. This can happen when the regulator falls from, or is removed from the mouth. There may also be an adjustment lever on a second stage that directly controls breathing resistance.     

Submersible Pressure Gauge (SPG)

The SPG acts as an indicator of how much gas is left in the cylinder. The units of pressure will either be in Bar or Psi. The SPG usually has different coloured zones, such as a reserve or caution zone. These are critical to dive planning, so an ascent can be made safely. Alongside pressure gauges the console can often include other gauges, such as a depth gauge, computer or compass.

Low Pressure Inflator Hose

This hose connects the first stage to the inflation mechanism on the buoyancy control device (BCD) and is what enables a diver to inflate their BCD. The attachment is made manually by clipping a metal sleeve, which is textured, into place. These attachments can come in different sizes, so its important to make sure the LPI will fit onto the BCD.     

Mares Atlas 62X Regulator (Pictured above)

Our recommendation is the Mares Atlas 62X. It’s great for divers of all levels, and is the perfect traveller’s companion because it ranks amongst the smallest of first stages without scrimping on performance. It’s well suited to either warm or cold water diving and is competitively priced. 

Mare’s products are well known for their innovative features and this regulator set comes with their unique vortex assisted design system, which allows high airflow and will provide you with easy breathing at all depths. With no moving parts inside, the chance of ice crystals forming when diving in cold water is not a problem.

The first stage comes with  4 low pressure and 2 high pressure ports and the dynamic flow control ensures steady gas pressure, even when under a heavy load (such as sharing air).

Mares Rover

This a great entry level option when considering a regulator. It is very low cost for what it offers. The 15X first stage has four low pressure and two high-pressure ports. It has a compact design, which does make it travel-friendly. Although not pictured on this post, it has a sandblasted finish.

The second stage utilises the Vortex Assisted Design to help with ease of breathing regardless of depth and the purge button is protected, which serves to minimise risk of free flow in currents.

Check out our store for more information on this regulator, as well as the many others we offer.