Dive Gear Guide: Choosing A Regulator

Posted August 26, 2013 by Charli Moore in Travel Tips

The first in our series of Dive Gear Guides, this article covers how to select a regulator that best suits your needs as a recreational diver.

Ranging in price, from a couple of hundred dollars to over a thousand, there are a range of brands and models to choose from.

So how do you work out which one to buy?

Test The Water

If you’re new to scuba diving, the best way to find out which products you prefer is to get your head under the water and test out some rental gear. Take note of the models you use in your training and consider how they feel during your dive.

Ask your instructors for their opinion, consult your local dive shop for their advice – some even let you demo the products they sell – and search for reviews online. However, remember that choosing a regulator is a very personal thing so don’t rush in and make a purchase without considering your options.

The regulator must constantly change the pressure at which it provides air to the diver.

So what should you factor into your decision?

When we talk about a regulator we’re actually discussing a number of mechanisms which when assembled, decrease the pressure of the air from the scuba tank and deliver it to the diver at the ambient air or water pressure.

The regulator must constantly change the pressure at which it provides air to the diver as both the pressure in the tank decreases – as the diver inhales its contents –  and the diver changes depth.

The main components are:

  • The first stage – the part that attaches to the tank.
  • The second stage – the part which supplies air to your mouth.
  • The alternate air or ‘octopus’ – a secondary air supply.
  • The inflator hose – an air supply to control the inflation of your BCD.

Din vs Yoke

Let’s start with the fitting that attaches the first stage to the tank.

There are two options. DIN and Yoke.

DIN fittings are safer than those using yoke as they screw into the tank valve and trap the high pressure o-ring so it cannot protrude. They are also the only fittings which can couple with high pressure tanks are therefore predominantly used in technical diving.

Yoke fittings are more commonly used in recreational diving and are almost always seen on the standard 80L aluminum tanks favored by dive operations around the world.

I would suggest that unless you plan to take up technical diving or prefer the DIN attachment, to select the yoke fitting for ease of compatibility when you travel to dive at new locations with your gear.

The First Stage

The first stage attaches to the tank and reduces the pressure of the air as it leaves the cylinder.

Comprised of two separate chambers, it receives air at around 3000psi from the tank and delivers it into a second compartment at around 150psi, known as the immediate pressure.

Balanced regulators deliver air at a constant intermediate pressure and are not affected by the ambient pressure.

The first stage is able to control the flow of air through either a balanced / un-balanced piston or a balanced diaphragm release system and this is the main choice you have when selecting a first stage.

Let’s look at balanced vs un-balanced.

When modern regulator design first emerged, there were notable differences in the performance of balanced vs un-balanced regs.

In short, balanced regulators deliver air at a constant intermediate pressure and are not affected by the ambient pressure or that of the air left in the tank. Those available on today’s market are almost indistinguishable once underwater so your decision is really piston or, environmentally sealed / unsealed diaphragm.





Piston Regulators

These usually let water into the first stage which means additional after-dive maintenance is required to avoid corrosion. However, they have only one moving component and so are incredibly durable and easy to service.

Diaphragm Regulators

Some are sealed from the environment which offer durability of function in cold water or while ice diving. This also offers protection against damage from debris, a consideration for those who enjoy quarry or go river diving.

However, with these benefits come additional moving components which require more in-depth servicing and yearly maintenance.

Scuba Diving Tubes

Flickr photo by Fredrik Stenbeck.

It essentially boils down to two things, price and convenience.

While the logistics of air supply underwater are rather complex, the process of choosing a reg doesn’t have to be.

Although, don’t forget to consider:

  • Availability of parts and servicing both in your local area and at the locations you will be diving.
  • The length and level of warranty offered with the product.
  • The weight of the components (if regularly traveling abroad to dive).

If you plan to dive predominantly in cooler climes or murky water, an environmentally sealed diaphragm is a must. Some sport divers, myself included, opt for an environmentally sealed diaphragm for a little more freedom with their dive itinerary and reduced after dive care.

If you do more warm water dives, minimal components and maximum durability appeal then a piston might be right for you.

The Second Stage

This is the part which goes in your mouth and supplies air on demand.

Like the first stage it is also designed to continue to reduce the pressure of the flow of air thus making it as easy as possible for you to inhale underwater. A diaphragm or piston design starts and stops the air flow as you breathe.





The main features are:

Comfort is a key consideration as it can affect your dive enjoyment.
  • The purge button, which allows you to rid the chamber of water should you need to, or free flow the air in the event of a malfunction.
  • The mouth piece, from which you breathe in.
  • The exhaust value, which allows your exhaled breathe to escape.





Comfort is a key consideration as it can affect your dive enjoyment, so when buying or testing out a second stage you should ask yourself:

  • Does this feel excessively heavy? – Remember that the regulator will become neutrally buoyant in the water thus reducing the apparent weight.
  • Do I have to bite down heavily on the mouth piece? – if so, it might be worth changing to a better fitting mouth piece or a different second stage design. Watch out for the new ergonomic mouth pieces which are said to allow you to maintain a natural jaw position and increase comfort during a dive.

The Alternate Air / Octopus

Another secondary stage regulator, the octopus, feeds off the first stage and is designed to offer a backup should your primary second stage malfunction, or to act as a life line to a buddy in an out of air situation.

It is worth ensuring that your alternate air source is clearly visible and easily accessible in an emergency situation.

It is worth ensuring that your alternate air source is clearly visible and easily accessible in an emergency situation. This can be achieved with a yellow hose and / or brightly colored mouth piece.

Many divers choose to reduce their initial outlay and opt for a more cost effective model for their alternate air source as it is likely it will not be used very often.

It is vital that you remember to maintain this as you do your primary air source. You never know when you might need it.

As an alternative, consider some of the more modern scuba designs which integrate the alternate air with the inflator hose reducing the need for additional hoses and streamlining divers in the water.

The Inflator Hose

The last element of the regulator the inflator hose feeds off from the first stage and provides inflation to the bladder of your BCD. When activated it feeds air into your BCD allowing you to manage your buoyancy at the surface.

While the logistics of air supply underwater are rather complex, the process of choosing a reg doesn’t have to be. Once you’ve decided what format suits your needs the rest is all down to personal preference.

Although the prices vary significantly, you should remember that all regulators and the companies that make them must conform to certain requirements so safety should not be quantified by cost.

The main comparisons can be made when looking at the quality of the components. The higher end models offer additional features such as air flow adjustment, lightweight design, Orthodontic mouthpieces, greater durability and are tuned for optimum air delivery.

Watch out for the next article in our Dive Guide Series where we’ll be looking at some of the best model of regulator at both ends of the market.

About the Author

Charli Moore

Travel writer and blogger Charli is a digital nomad currently travelling the world with her other half Ben. Whether backpacking through Central America or road tripping around Australia they embrace each and every opportunity for adventure. Read more about their insatiable wanderlust on their blog, Wanderlusters.

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