When you go diving you need to know how much air you have left in the tank, it is essential and will keep you alive.
Every diver should be using a submersible pressure gauge (SPG), gone are the days of the J-Valve. The SPG should be easy to read and in good working condition.
There are a few different types of SPGs and some are simpler, just an air gauge with a fluorescent/ luminescent display and large numbers and markings.
Others have multiple features like a compass, temperature gauge, or a display with colors specific to a depth.
We will help you to find the right style of SPG and answer all the questions like how long should the hose should be to whether to have oil or air inside.
How to use an SPG
When you open your air tank face the glass of the SPG away in case of failure. The tank should be filled to around 3,000 psi (200 bar), it varies depending on the operator and other factors like temperature.
You need to be looking at your SPG throughout the dive and monitoring your air. Keeping your buddy updated with hand signs and following the Rule of Thirds is also a good protocol. When the gauge gets down to around 700 psi (50 bar) you come back for your safety stop and surface.
SPG Buying Guide
The nice thing about looking for an SPG is that there are not an overwhelming number of options. In general the simpler the better as it leaves less chance for failure. With the advancement of dive computers, you don’t always need all the bells and whistles on your SPG.
The reason people do have these is redundancy and a safe option if something was to go wrong with your dive computer.
Basic Features of an SPG
You want it to be easily read underwater and preferably color coded (or at least the red). Green for a full tank, yellow for a half tank, and red for 50 bar and below. This makes it easy to understand in any situation.
The second feature is that it should be able to be illuminated at night and seen in low light. The needle should be florescent and the face luminescent.
You can charge the dial and your face easily by pointing your flashlight at the face.
The last is that it should not be too long and be able to be secured easily.
This will prevent it from dragging where it can get caught on objects or hurt wildlife.
SPG Options
Standalone or Console
The most common set-up of SPG is a standalone. These have only one point of failure and still do the job correctly. The console type has 2 or three other gauges usually a depth and sometimes a compass on top. Even people with air-integrated dive computersto read air have the standalone as a backup.
Stripped Down or Booted
Booted means they are covered with plastic or rubber which gives more protection and prevents wear and tear. Stripped-down SPGs are just the exposed metal that creates less drag but needs extra care when handling it so it doesn’t hit objects or get crushed.
Materials
Brass is one of the most common materials used together with tempered glass and rubber. This stops it from rusting and is very durable. There are other materials out there for the face like Noryl and Lexan and different metals as well. Make sure to read up on what it is made of, the better the material the higher the cost, and the safer you will be.
Analog Compass
You can get a dive compass for your wrist some SPGs have the option to add them on. You will see most divers with these as it doesn’t require batteries or be calibrated.
Imperial, Metric, or Both
The United States is basically the only place that uses the Imperial system. The pressure gauges there usually have only PSI.
Metric is the other system and is easier to use as the numbers only go up to around 220. It can be confusing to convert Imperial and Metric numbers. If you do travel and for ease having an SPG with both would be a good idea.
Fluorescent Dial
A fluorescent dial takes the light available from the sun or flashlight and reflects it. This makes the dial neon and easily visible underwater.
Color Indicators
Luminescent Face
This is a fancy word for glow-in-the-dark face. You can make it brighter by shining your light on it and charging it.
Recessed Instruments
This option is good to protect your gauges. It prevents them from getting scratched or smashed underwater or traveling.
MDI Needle
A maximum depth indicator (MDI), will help you to remember your maximum depth if your dive computer does not have an alarm or it fails. You don’t want to go too deep and past your maximum depth and build up too much nitrogen which can lead to DCS.
Where is a scuba pressure gauge attached?
The SPG gauge goes from a hose to the high-pressure port. It needs to be secured and attached properly. If it comes off or the line breaks the air from your tank will flow out quickly. It also may sound like a gunshot when it happens.
While diving is safe these things do happen so dive with a buddy.
- Lightweight/ Compact
- Chrome-plated brass for maximum durability
- Easy-to-Read with Color Coding
- Hose not braided
- Only Metric or Imperial
- No Depth gauge
The Cressi Console CP2 is a compact SPG that is easy to read with a bright color gradient that is easy to read and you can reference quickly.
The analog compass is at the perfect angle to use when reading the face or the side window. The console has 2 connection loops at the top and the back to be able to attach to your BCD to help become more streamlined.
It goes up to 5,000 PSI but does not have a depth gauge. It is booted in a rubber casing that is recessed to give better protection. The actual SPG is made from chromed brass and is light and perfect for travel as well.
- Nitrox compatible
- Integrated Temperature Gauge
- Shock resistant
- Hose not braided
- Only Metric or Imperial
- No Depth gauge
This SPG is our pick for standalone as it is durable and simple while still being functional at a solid price point. You can get it in Metric or Imperial so you can take it anywhere in the world.
The OceanGlo® luminescent backing lets you be able to see it clearly in low light and in the dark. You can also hook up to 50% Nitrox to the gauge with no issues. The one-way safety valve gives you extra peace of mind. It also has a temperature gauge on the face as well.
- Lightweight/ Compact
- Cheap
- Easy-to-Read
- No extra protection
- Only Metric or Imperial
- Does not come with a high-pressure hose
This single gauge SPG is made from nickel-plated brass and tempered glass so it will stand up in rough conditions. It still has a fluorescent dial so you can still see it underwater in all conditions and the luminescent face allows for easy reading.
The SPG comes in different sizes so there is something for everyone. A lot of divers that go to challenging dive sites like caves or wrecks use it for its reliability and simplicity. It won’t get caught and you can keep streamlined.
- Lightweight/ Compact
- Chrome-plated brass for maximum durability
- Easy-to-Read with Color Coding
- High Price Point
- Only Metric or Imperial
- Weighs 1.1 pounds (.5 kilos)
The console combines a has a pressure gauge, a depth gauge, a temperature gauge, and a compass all in one. It is booted and housed in compact plastic for extra protection. The Scuba 3-gauge In-line diving console is for divers that want convenience and to have everything in one place.
The depth gauge is oil filled and easy to read with red to notify you when you get into that area. The compass is on a 26-degree-tilt for ease when using it and oil-filled for reliability and accuracy.
- Full Color Display, High Resolution
- 15 color options available
- Intuitive settings + easy to read display
- Switchable audible and vibration alerts
- Supports open-circuit, fixed
- PO2, gauge, and freediving modes
- Can be worn as a regular watch
- Simple yet stylish design
- Lightweight
- 2 transmitter connectivity
- Rechargable battery
- High price
- No transmitter included
This wireless is the top-of-the-line for wireless SPGs. You will need to have the Shearwater Teric Dive Computer to use it though. It has all of the features that you would ever need from simple things that all computers have like GTR (NDL no-decompression limits), to your SAC (surface air consumption) rate.
These things can be planned and input into your computer but are not measured until the first few minutes of a dive. Then the SPG and computer collected the data for estimates.
The transmitters are not made for pure O2 and should only be used with nitrox mixes up to 40% O2. The tank pressure can be shown in PSI or Bar. You do have to be careful as if you hit the transmitter it can break off and it cannot be fixed.
