Scuba Octopus Setup


The Scuba Octopus Setup may seem a little daunting at first, which is why Diving Squad are here to help.

But wait, hold your sea horses! What the hell even is a scuba octopus? 

The Scuba Octopus Setup constitutes a diving regulator (which delivers pressurised oxygen to your mouth via a dive tank), a spare regulator, plus your scuba diving gauge.

Understanding the scuba octopus setup – which pieces perform what task and how to apply and use them; is essential to being a scuba diver.

You need to make sure that you can trust your scuba octopus setup, as this controls whether you are able to breathe underwater or not…pretty essential right?! 

Ok Squad – Let’s Dive in!

Scuba octopus
Not THAT kind of Octopus!

Attaching Regulator to Scuba Tank

Before diving in, it’s vital that you take special care and attention when assembling your scuba diving gear.

Preventing equipment problems during a dive is a major aspect of this sport!

Once you have your scuba octopus setup ready, you’ll need to safely and securely attach it to your scuba tank.

Newby divers might run into some hiccups in the beginning, but over time and with practice it becomes a really easy task.

First, you will need to attach your cylinder to the Buoyancy Control Device (BCD). Then you’ll need to attach the regulator to the cylinder valve.

Remember, the first stage of the regulator is what attaches to the air tank, so this is where you will need to focus. This is achieved through a yoke or DIN fitting. Read More about These Parts here! Then it’s just a matter of opening the cylinder valve and testing out the unit before your dive.

If you’re unsure about how to attach your regulator to the tank, be sure to get help from a dive professional. They will make sure that your dive gear and scuba kit is safe for use.

How Does a Scuba Regulator Work?

Cute Scuba Girl going through her Scuba Octopus Setup
Giving that Scuba Octopus some Sweet Luvin'

Scuba tanks are filled with compressed air at an extremely high pressure.

Trying to breathe directly from this is not possible, and would result in injury.

The scuba octopus setup, or regulator, reduces the pressure of this compressed air to a pressure that the diver can safely breathe.

The scuba diving regulator takes pressurized breathing gas or air from a tank and reduces it to an ambient pressure (this is the pressure that we can breathe in).

This is achieved by the air traveling through a series of hoses and valves.

The regulator then sends this breathable air to the diver.

As mentioned above, the scuba octopus setup works with two main stages: first stage pressure reduction and second stage pressure reduction.

It is important to understand the difference between these two stages, and which valves and hoses work to control them.

First Stage Pressure Reduction

This initial stage of pressure reduction takes the super high-pressure air or breathing gas from the tank, and lowers it to an intermediate pressure.

This is the first step in creating breathable air, and it is achieved through a few parts.

When looking at a typical open water style regulator, the first stage connects to four different hoses.

One of these channels the high-pressure air directly from the tank and into a submersible pressure gauge.

The other three hoses channel the intermediate pressure air to the second stage, and to the buoyancy compensator (BC) inflator.

Second Stage - Pressure Reduction

This guy does't feel any pressure, because he know's all the pressure stages in his scuba octopus are working!

This is the part of the process that turns the pressurized air into something which we can breathe. In the second stage, the intermediate pressure from the first stage is then lowered to an ambient pressure.

The ambient pressure matches the pressure of the water surrounding you, and this is what is safe for the diver to breathe.

This is achieved through the pressurized air traveling through a regulator hose, which then gives the diver access to breathe from.

The second stage can be broken into a primary second stage and an alternate second stage.

These are the same thing really, except that the alternate second stage acts as a kind of emergency air source to those who may have run out of air or in an emergency.

Scuba Regulator Setup: Scuba Regulator Diagram

The regulator in your scuba diving kit is generally made up of five basic scuba diving parts. These different parts are all connected together with hoses, and work together to allow you to breathe.

Photo Credit: Natilie L Gibb @

First Stage

This is the initial mechanism involved in the scuba octopus setup. This part attaches directly to the scuba tank, and does what its name suggests – achieves the first stage of pressure reduction.

The intermediate pressured air then travels through the low pressure (LP) regulator hoses to reach the next parts. Even though this air is of a lowered pressure, it is still not safe for the diver to breathe.

Primary Second Stage

This is the part of the setup which the diver puts in their mouth and breathes from. This part is attached to the first stage by the LP hose.

As the name suggests, this part of the regulator works as the second phase of air pressure reduction, and transforms the air into a breathable ambient pressure.


Alternate Second Stage

This part of the scuba octopus setup, also called a buddy regulator or an alternate air source, is basically the same thing as the primary second stage.

It does the same job through the same process as the primary second stage, however, it is used as a backup.

In the case of emergency, such as a fellow diver running out of air, the alternate second stage can be used to allow them to share from your air tank. This part is also attached to the first stage with a LP regulator hose.

Submersible Pressure Gauge

This part of the scuba octopus setup is crucial for your safety underwater. The submersible pressure gauge and gauge console allow the diver to check how much air they have left in their tank to make sure they don’t just run out of air underwater.

A high pressure (HP) hose connects this pressure gauge to the first stage in the regulator. This hose sends HP air directly from the tank to the gauge.

The gauge console also houses other useful gauges, such as a dive computer, depth gauge or compass.

Low Pressure Inflator Hose

The buoyancy compensator (BC) inflator is fed intermediate pressure air from the regulator first stage through this LP inflator hose. This gives the diver the opportunity to add air to their BC directly from tank when they want to.

Still Reading about my Evil Cyborg Twin? Great Job!

Scuba Regulator Parts

The scuba octopus setup consists of five main sections. Within these different sections, there are a variety of important pieces and parts which work together in order for your regulator to be successful. It’s a seriously good idea to get to know your scuba equipment and exactly what it consists of.

First Stage Parts

All of the mechanisms which lower the air pressure to an intermediate pressure are housed in the first stage body.

This is a metal cylinder through which the air enters, the pressure is reduced, and then leaves to go through the second stage.

Scuba Regulator Parts
Let's Take a Closer Look.

A Yoke or DIN fitting then attaches the first stage body to the scuba tank. This comes with a Yoke Screw which tightens the regulator onto the tank.

A Dust Cap is a small rubber cap which is positioned over the regulator first stage opening and tightened down using the yoke screw.

This dust cap is crucial as it prevents water from entering the regulator first stage body by sealing closed the opening on the first stage.

Ports and Port Plugs are found all over the first stage body. These are where the different hoses are attached to. If the port is not in use, it will be covered by a port plug.

There are often more ports than what is actually needed, so you can position the hoses in the way they like.

Primary Second Stage Parts

The purge button is found on the face of the regulators second stage. This button allows the second stage to flood with air, forcing any water out of the second stage.

The button is used when the second stage has been removed from the mouth and may fill with water. 

The ease of breathing adjustment is found on most regulators, and it allows divers to adjust their breathing resistance through a knob or lever.

This adjustment helps to avoid free flow, which is when the air flows continuously out of the second stage regardless of the diver’s breath.

An exhaust valve is located on the second stage and works to channel any exhaled air bubbles away from the divers face.

This is found below the mouthpiece and helps you to keep a clear vision. Then there is the mouthpiece. This is the part that the diver puts their mouth on to access air.


Alternate Second Stage Parts

This part of the scuba octopus setup works exactly the same way as the primary second stage. While it consists of the same parts, it is connected by a low pressure hose.

An LP hose transports the intermediate air from the first to the second stage. An alternate second stage LP hose is usually longer for ease of use by another diver if needed.

Low Pressure Inflator Hose Parts

Where the low-pressure inflator hose attaches to the buoyancy compensator inflation mechanism, a sleeve is used.

This metallic sleeve needs to be held back when connecting the hose to the BC inflator. They are usually textured for easier grip in the water.

The attachment opening connects the BC inflator to the LP hose. These come in a variety of sizes.

Submersive Pressure Gauge and Console

The Submersive Pressure Gauge (SPG) is what you’ll use to monitor how much air is left in your tank. This gauge is often part of a console which consists of a variety of useful tools to the diver.

These can include a depth gauge to monitor your current depth and maximum depth, the SPG showing you how much air pressure is left in your tanks, a compass and dive computer.

Scuba Regulator Maintanence

Scuba Octopus Setup
Best done out of the Water.

Scuba octopus setups are complex but reliable mechanisms.

The scuba octopus setup should definitely give you years of good use. In order for this to happen though, you’ll need to keep your regulator well serviced and maintained.

Any local dive center should be able to take your dive gear in for all necessary services. Once a year should be enough for most divers, but if you dive more often than most, perhaps more frequent services are necessary.

Dive shops often refer to this service as a “tuneup”. While this sounds simple, there is actually a lot of work that should be done for it. Your entire scuba octopus setup will need to be disassembled, inspected, replaced where necessary, cleaned up and reassembled.

This often includes replacing and lubricating threads and O-rings, tending to any possible salt damage, and adjusting and replacing valves, connections and hoses. Make sure that your gauges are also checked in your annual service!

If you use a more popular brand, you’ll find that it’s actually far easier to service and find parts for them in remote locations. Therefore, if you plan on traveling a lot with your scuba gear and diving in far off places, having a better-known brand may be wise for servicing reasons.

Scuba diving relies heavily on the equipment. In order to maintain a good level of safety, and avoid any possible emergencies, it’s vital to have your gear regularly serviced, checked and tested by professionals.

If you tend to use your diving equipment seasonally, it’s best to have your scuba octopus setup serviced before you put it away for storage. This prevents any salt damage which could occur while it is not in use.

Some Folks love their Scuba Octopus so much, they even keep it in their mouths out of the water...

Diving Squad Debriefing

And there you have it! Everything you’ll ever need to know about the scuba octopus setup! We’ve covered what this essential piece of gear does, how it works, it’s components and how to look after it. 

That’s all for now folks. 

Written by:



Scuba fanatic. Travel ecstatic. Erratic. The name's Alex.

Similar Articles: