Scuba regulators are what allow you to breathe underwater, so selecting your regulator is very important for your overall safety on a dive. Since regulators are so important, it’s no wonder that manufacturers have created regulators in an array of styles, designs, and shapes. Despite all these differences, however, all regulators have the same basic parts: air hose, first stage, and second stage. Generally, you will buy the first stage separately from the rest of your regulator. The first stage of your regulator attaches to your tank with either a DIN fitting or a yoke fitting, regulating the air pressure before it reaches the air hose from the tank. The second stage delivers air and removes waste. This second stage consists of a purge valve and a mouthpiece.
When shopping for your regulator, there are several things to look for:
1) Assembly. Diaphragm assembly and piston assembly are the two choices here. Both options reduce air pressure in the first stage and both options have pretty much the same advantages in moderate conditions. However, if you ever need high air flow, the piston assembly will allow you much more air than the diaphragm. Piston regulators tend to be more expensive and tend to have fewer moving parts, but offer a superior air flow rate when compared to diaphragm regulators. Piston first stages, however, are less expensive and tend to be more reliable. Diaphragm regulators do offer less impressive performance, but they are also less expensive, and for many recreational divers, diaphragm regulators have more than enough power and air flow. Also, divers in cold waters generally like diaphragm regulators, because in cold water conditions diaphragm regulators are less likely to free flow.
2) Easy to use purge button. The purge button allows you to clear any water from the second stage by forcing air through the regulator. Look for a button that is easy to reach and easy to use with only one finger, even when you are wearing gloves.
3) Coupling fittings. The regulator’s first stage is attached to the tank using either a Yoke fitting or a DIN fitting. Although Yoke fittings are more common, DIN coupling fittings are actually considered safer. They are also the only fittings you can use if you want to use high-pressure diving tanks. DIN fittings also trap the o-ring so that it cannot protrude. You can use a Yoke adaptor with a DIN regulator, and Yoke regulators can be outfitted with a DIN adaptor. However, it is important to have DIN adaptors installed only by good scuba repair technicians.
4) Balanced vs unbalanced regulators. This is one area where almost all divers agree: balanced regulators are best. Balanced regulators allow for a regulated and steady breathing experience underwater. Unbalanced regulators will mean struggling for breath a little on deeper dives and when your air tank depletes. Balanced regulators are more pleasant to use because they equalize air pressure on two sides of the air valve, so that you can breathe steadily, even at different tank air pressures and at greater depths. The only drawback to the balanced regulator is that it is more expensive. However, the expense is well worth it for a higher quality dive experience.
5) Mouthpieces. Most mouthpieces are made from hypoallergenic silicone and come in different sizes. You will want to find one that fits comfortably in your mouth. An ill-fitting mouthpiece affects the quality of your dive and can even lead to jaw aches. You may also want to look for an ergonomically shaped mouthpiece. These types of mouthpieces claim to allow your jaw to remain in a natural position. This can help reduce jaw aches after a dive and can make your mouth more comfortable. When selecting your mouthpiece, buy a spare. Mouthpieces wear out quickly, especially since many divers bite down harder than they need to on them.