For every diver, managing to achieve perfect neutral buoyancy is the epitome of success – and it all starts with knowing the type of scuba divers tanks that you’re using.
Without these high-pressure cylinders that contain large volumes of air, any form of scuba diving as we know it would be impossible.
However, scuba divers’ tanks are a piece of diving equipment that gets overlooked the most by both beginners and pros alike.
Regardless of whether you plan on buying your own set of tanks or not, having some basic knowledge about scuba tanks – and the difference between steel and aluminum – will take you a long way.
Why? Because some dive schools give you the option of choosing between the two, but – more importantly – you will get an overall better understanding of basic diving equipment that will help you plan better, safer, and more comfortable dives.
Steel VS aluminum scuba tanks
As a diver, you know that every piece of diving equipment comes with many options. Be it a mask, reg, BCD, or fins, there are different models available on the market to fit your specific diving needs and preferences.
When it comes to scuba divers’ tanks, you have the option between steel and aluminum.
So let’s talk about the difference between these two materials, the pros and cons, and how they can affect your dive.
- Weight of scuba tanks
With scuba tanks usually weighing between 24 and 34 pounds, choosing the right type of tank is an important consideration, especially for remote diving. After all, if you have to carry your tank for a significant distance, why not choose a scuba tank that weighs less?
Aluminum tanks need to have thicker walls to hold the same air capacity as steel scuba tanks, so when compared to steel cylinders, aluminum scuba tanks are heavier out of the water.
2. Durability & damage-resistance of scuba tanks
A choppy boat ride, sea currents, and ordinary wear and tear are all it takes to damage your dive gear.
Steel scuba tanks are harder and more resistant to external damage. That’s why in some parts of the world you’ll only find steel scuba tanks.
On the flip side, however, without proper maintenance, steel scuba tanks are more likely to rust, especially if exposed to saltwater (ironic, right?).
By contrast, aluminum is a softer metal and thus more prone to dents, scratches, and cracks. However, aluminum scuba tanks are much more resistant to saltwater corrosion, making them a very popular choice in most parts of the world.
3. Buoyancy of steel and aluminum scuba tanks
As first mentioned, the scuba tank that you use will directly affect your buoyancy and weight requirements.
Here is how it works: steel tanks are more negatively buoyant than their counterpart and will remain so even when they’re empty. A big advantage of this is that you have to carry less weight on you.
Aluminum scuba tanks are also negatively buoyant, but as you consume air, they will gradually become more positively buoyant. So avoid a rapid ascent at the end of your dive by taking into account this slight change in buoyancy level. This will ensure that you remain neutrally buoyant throughout your dive and can safely complete your safety stops.
4. Sizes of scuba divers’ tanks & air capacity
The size of your scuba tank is something you definitely have to consider when:
- You’re young or on the shorter side
- You consume a lot of air
- You’re just starting out
The size of the scuba tank refers to its physical dimensions, but also to how much air it holds at different compressed air pressures, ranging from 2400-2650 psi (low pressure) to 3000 psi (standard pressure) and 3300-3500 psi (high pressure).
The size of the tank is measured in cubic feet or liters in the metric-using countries. Depending on where you dive in the world, the most popular scuba divers’ tanks are called:
- 80-cubic-foot aluminum (AL 80) – 12L Aluminum
- 100-cubic foot aluminum (AL 100) – 15L Aluminum
- High pressure 80 (HP80) – 10L Steel
- High pressure (HP100) – 12L Steel
- High pressure (HP120) – 15L Steel
What does all this mean in practice? The higher the tank capacity, the more air you’ll have to enjoy longer dives!
For example, if you indulge in longer dives and/or have a higher air consumption, you might want to consider a higher-pressure tank. Steel tanks are usually the preferred choice because they can withstand higher pressures. Plus, they’re lighter and more compact.
Conversely, if you’re on the shorter side, only do shallow dives, or have a low air consumption, you might be happy with a low-pressure steel scuba tank. Steel cylinders are generally shorter than aluminum tanks, so you don’t have to go through the discomfort of hitting your head or legs on the tank while scuba diving.
5. How much do scuba tanks cost?
Aluminum tanks are usually cheaper than steel tanks, making them the go-to choice for many recreational divers looking for reliable and budget-friendly scuba divers’ tank.
Important: regardless of the scuba tank you choose to use or by, proper handling and care are essential. It’s as simple as rinsing it after a day’s dive, preventing any moisture from getting in during refills, and having it inspected and tested regularly.
Steel VS aluminum scuba tanks: which one is better?
To sum it up, steel scuba tanks are lighter, more durable, and take a few pounds off your weight belt. Aluminum scuba tanks are heavier, more positively buoyant, and much cheaper.
If you’re still on the fence as to which scuba divers’ tank is best for you, just try them out. Next time you go diving, ask your dive shop what scuba tanks they have – and rent them. With each tank, you’ll notice its physical differences by just lifting it, carrying it, and setting it up. And when you’re actually underwater, you’ll feel how different scuba divers’ tanks have different air capacities and buoyancy levels.
Even if you have no intention of buying your personal scuba diving tank, having some knowledge about scuba tanks will enrichen your dives to make them more comfortable. It will a) help you determine how much weight you’ll need to be neutral buoyant, and b) give you more confidence in your diving knowledge and skills.
As for most of the diving equipment, there is no “better” option, just personal preferences that work around your diving needs. The most important thing is to pick the tank that works for you. Which one will you choose?