Which Size Steel Scuba Cylinder Is Right For You?

Divers in cooler temperate waters most commonly use the following three Faber steel tank sizes:

Faber 10.5 Litre (85 cubic foot), 232 bar — This smaller cylinder size is preferred by many women because it's lighter and easier to handle. If you are a diver with a very good surface air consumption rate, as many women are, then this cylinder has enough air capacity for most dives. A pair of these steel tanks is also popular with sidemount divers, and women technical divers.

Faber Standard 12.2 Litre (100 cubic foot), 232 bar — This standard size, 178 mm (7 inch) diameter, cylinder size is used by the vast majority of divers. A pair of these cylinders is also the most common choice for technical divers.

Faber Standard 15.0 Litre (125 cubic foot), 232 bar — This larger size, 204 mm (8 inch), cylinder size is the choice of divers with a poor surface air consumption rate. However, it's larger size and weight makes it awkward for many divers to use.

Faber 3 Litre (25 cubic foot), 232 bar, 100 mm (3.9 inch) diameter, are the popular choice of rebreather divers.

Low and High Pressure Steel Scuba Diving Cylinders

Faber Low-Pressure Steel — 232 bar — Lighter on land than standard aluminium scuba cylinders, these Faber 232 bar steel cylinders feature a higher working pressure than most aluminium cylinders, thus delivery a larger gas capacity for the same internal volume. The 232 bar Faber cylinders come equipped with a DIN/K type valve that easily converts back and forth depending on the type of First-Stage Regulator to be used in conjunction with the cylinder increasing the versatility of the tank. When diving with these cylinders less weight is needed, making them perfect for divers that use drysuits, or wetsuit divers in cold/temperate waters. The Faber steel cylinders are popular for cave diving and have a strong following among technical divers everywhere. The average working pressure is 232 bar.

Faber High-Pressure Steel — 300 bar — Much heavier than standard aluminium and steel scuba cylinders, these Faber 300 bar steel cylinders use much higher working pressure to provide a huge gas capacity in a small size. Like their low-pressure steel cousins, less weight is needed with these cylinders. A favourite with wreck divers, the average working pressure is 300 bar.

Faber is the leading manufacturer of steel scuba cylinders in the world and is the market leader in Europe and Australia where diving with steel cylinders is the norm. Faber's cylinders are manufactured from deep drawn 34CRMO4 Chromium Molybdenum steel plates to ANSI specifications. This process results in a light cylinder with the right buoyancy characteristics allowing the diver to reduce the amount of weight from their weight-belt. The interior of the cylinders are shot-blasted followed by their exclusive phosphatised coating which creates a perfectly cleaned internal surface, highly resistant to rust. The exterior of the cylinder is triple protected with zinc spraying, epoxy primer coat and polyurethane finish coat for durability.

The service life of a properly cared for modern steel scuba cylinder is widely considered to be 50 years or more. The service life of a properly cared for aluminium cylinder is more controversial. Most dive shops, including The Scuba Doctor, won't fill an aluminium tank manufactured before 1990.

The Scuba Doctor carries an extensive selection of Faber steel cylinder sizes starting with the 2 litre (16 cubic foot) all the way up to the 18 litre (150 cubic foot) cylinder. Faber cylinders are available in 8-inch, 7.25 and 7-inch diameters with working pressures of 232 bar and 300 bar.

All dive cylinders from The Scuba Doctor dive shop are visually inspected and shipped with a current hydrostatic date (except where indicated).

Buoyancy Control

Scuba diving happiness is fine buoyancy control and good trim

This is a buoyancy control exercise, not meditation. Try it sometime.

Scuba diving has three essential skills: breathing, buoyancy control and surfacing before the gas supply runs out. All other skills are add-ons, although they will make any dive more comfortable and safer. Of the three major skills, breathing will have been mastered prior to scuba training, and surfacing before the gas supply runs out should be fairly easy to master. The major scuba diving skill to learn and keep monitoring is buoyancy control.

How do you decide if your own buoyancy control is good? Do you sink or ascend if you stop finning? Are you known to kick silt up? Can you ascend a shot line without holding on? Can you hold a 3 or 5 metre safety stop at the end of the dive, with low cylinder contents?

Here's a simple test. Swim horizontally at an underwater object. If you breathe in slowly, you should rise slightly, and if you breathe out slowly, you should sink slightly. Do you?

Does it matter? Well, many diving incidents have deficient buoyancy control at their core. So yes, it matters!

Get Your Dive Weighting Right

We recommend you record the gear you use and the lead dive weights you're using for every dive in your logbook. Thus you can easily lookup what dive weight you should need for different dive equipment configurations.

Then you check your buoyancy and trim in the water. If you think it's a bit off, make a mental note to do a proper buoyancy check at the end of the dive. With 50 bar left in your cylinder(s) (dump air if necessary to achieve this), you want to be neutrally buoyant at 3 metres with no air in your BCD. (Shallow water pier and shore divers might want to make that 1 metre.) If that's possible, then your ballast weight is correct for the dive gear configuration you're using. Of course, if you're in a dry suit, you also need to have very little air in your dry suit. Just enough to prevent pinching, no more.

See Perfect Scuba Diving Weighting for more detail about doing a proper buoyancy check, plus our Dive Weights Buying Guide for help choosing the best diving weight system.

Setting Buoyancy Control Goals

You can steadily get better at this buoyancy control lark. What helps is setting goals.

Buoyancy control range chart An initial goal would be getting close to you being 100% confident you can maintain a position in the water +/- 1.0 metres, no matter what happens.

An intermediate goal would be to stay within a +/- 0.5 metre range of your desired depth.

A challenging goal would be to eventually expect you being able to do better than this and get to +/- 0.2 metres, even in very stressful situations where dive buddies are panicking, whilst multitasking (which of course for anyone is virtually impossible even when on dry land!), gas switching, shutdown drills at a 3 metre stop, mask clearing, and deploying DSMBs. But it's going to be a long process to get there.

The first rule is to try to keep breathing normally, instead of falling into the trap of holding your breath when concentrating on a task.

And you need to be progressive. Don't try and maintain your buoyancy within too tight a range at the beginning. Aim for +/- 1 metres at first. Then +/- 1 � 0.5 metres, and finally +/- 0.2 metres.

Try and get it a bit better on every dive, but don't become too obsessive. Of course, when you think you have really sussed it, something will happen to shatter your confidence.

Once you think you have a goal sorted, start to task load yourself by checking your gas, or writing on a slate with a reference in sight such as the bottom, or a marker on the shot line, and then moving on to deploying DSMBs.

Good Trim

Buoyancy Control and Good Trim

Make sure your trim is correct. By this we mean adjust your weighting and kit configuration so you can sit totally horizontal in the water and totally stop finning whilst maintaining your buoyancy. It's more difficult that it sounds.

Good buoyancy and trim is so important because a relaxed and comfortable scuba diver is experiencing very much lower stress levels, both physical and psychological. Consequently such a diver is much more able to deal with any unforeseen problems in a logical and methodical way, use less gas, reduce his/her propensity to suffer many diving ailments and enjoy their diving more.

Diving happiness is fine buoyancy control and good trim. After all, one of the attractions for many in diving is the enjoyment of the feeling of weightlessness underwater. The ability to move almost effortlessly in three dimensions once achieved properly, not only makes diving easy, but also allows you to do other things, like take pictures or resolve minor problems, without task loading.

If scuba diving was a competitive sport then skills based around perfect buoyancy control and good trim would be a key part of any competition. A few years back DAN Europe ran a MasterTrim contest with the support of the Green Bubbles Project. Maybe this should happen more.