Your regulator is your air delivery system. It converts the high-pressure air in your cylinder to a breathable pressure for the depth you are at and pressure that you are under. On a very simple level, the more expensive the regulator, the easier it will breathe.
A regulator set is made up of a few separate pieces. The first stage is the part that attaches to your tank, and its job is to convert the pressure to an intermediate level. The second stage is the part that you breathe from; it turns the intermediate pressure to the surrounding pressure so that you can breathe. Your octopus or alternate regulator in a secondary second stage. To complete the set you will need one or two low-pressure hoses for inflating your BCD and dry suit if you are using one and a high-pressure hose to attach to your SPG to show your tank pressure. Typically your high-pressure hose and SPG are a separate purchase.
What you choose will depend both on the type of diving that you are doing and also the amount of money you have to spend.
- First Stage
First stage design falls into two categories, piston, and diaphragm. Honestly, at recreational depths, there isn’t much to choose between them. If you are considering technical diving in the future, then most technical divers prefer a piston design as there are less moving parts.
Where you will find the difference in how a regulator breathes is between a balanced and unbalanced set. A balanced regulator delivers air at the same rate no matter what depth you are whereas you will find an increase in resistance at depth when breathing from an unbalanced set.
First stages connect to the tank using a yoke/A-clamp or DIN fitting. A DIN fitting screws into the tank whereas a yoke sits flush to the valve. Again deep divers prefer DIN fittings, but both are fine at recreational depths. If you buy a DIN fitting, you can buy an adapter to convert it to a yoke style. Many scuba tanks can convert to fit either style, but it does require the correct Alan key to remove the tank valve insert and allow the tank to function with a DIN valve. Always check what style is available when you dive somewhere new.
If you are going to be diving in cold water, you will need a regulator that is environmentally sealed to protect it from freezing. Further, you will need to make sure that the first stage has enough ports to allow for two low-pressure hoses, one for your BCD and one for your dry suit.
The final design feature that some first stages offer is a swivel which allows a rotation of the turret which can help with ease of hose positioning.
- Second Stage
Second stages can be balanced or unbalanced too. Again, a balanced set it going to breathe easier at depth than an unbalanced second stage. Most second stages have a device for controlling air flow, and some have an inhalation adjustment too so that you can alter the effort required to activate the demand. This lever can be adjusted at depth to make the effort the least but also for the surface to make free flow less likely.
You’ll probably find that your first stage and the primary second stage will be sold as a set and that your octopus or alternate will be an additional purchase. Most divers opt for a lower spec alternate with a yellow hose and fascia for easy location. It is possible to incorporate your alternate into your BCDs inflator system which would eliminate a hose.
Regulators are a heavy item to pack and travel with. Manufacturers now offer regulator sets made from lighter weight materials. If all of your diving is on holiday, then it’s wise to consider this option. Most travel regulators are only suitable for warm water diving.
It’s fair to say that even the cheapest regulator will be adequate if all it is ever going to be used for is diving at recreational depths in warm water. You will find more breathing resistance at 35m than you would at 5m, but it would hardly be a chore. However, your regulator will last you a long time, and if you plan to progress to other types of diving, then you might want to consider buying for the future.
If you can, try some regulators out. Many retailers have sets available for this very reason. When you hire regulators take note of the make and model. Ask around too; it’s quite often the case that a diver who loves their regulator will let you take it for a spin, just to prove how fabulous it is.