Scuba is an acronym that stands for “Self-Contained Underwater Breathing Apparatus”. Over the years it has been converted to a word. Before the invention of a demand regulator, divers would have air pumped to them from the surface. Now, with the use of a demand regulator, divers can take their air supply with them in dive tanks. There are several manufactures of dive tanks also called cylinders. There is also a variety of sizes and a selection of materials that tanks are made of. The most commonly found, however, is the aluminum 80’s.
Whether it is better to rent your tanks or have your own depends on your circumstances. We will discuss that in the guide at the end of this buying guide. For now, let’s look at what we see as the best dive tanks on the market.
- When choosing a dive tank, consider the size in comparison to the diving you’ll be doing. Smaller tanks will drain air quicker, but if you only dive in shallow locations, that might not be an issue. The smaller the tank, the easier it is to store and transport.
- Aluminum tanks are your best bet when shore diving frequently, as they are positively buoyant, lightweight in comparison to steel, and easily transported while wearing them on land.
- Do not pay extra for a special tank - nowadays, tanks are compatible with up to at least 40% Nitrox.
Scuba Diving Expert
How To Choose A Scuba Tank – Buying Guide
The manufacturing of compressed air tanks, including scuba tanks, is tightly controlled. Each air tank must meet stringent standards and the test result embedded into the material of the tank. The US Department of Transportation (USDOT) standard is required in the US and has been accepted in most countries. Every tank is required to have a visual inspection each year which is recorded on a sticker attached to the tank. Also, every five years the tank must have a hydrostatic test. If a tank does not have all of these requirements, it is illegal to fill the tank with compressed air.
The standard 80 cubic feet (cf) is the most commonly used size by recreational divers. This is what typical diving companies rent out. The size represents the amount of air that can be compressed into the tank at the rated pressure of the tank. Opting for a larger tank, 100 cf, is an excellent option for those who consume a lot of air or who are going on longer dives. Choosing a smaller 63 cf tank is a great option for children as they will not need as much air. Here is a basic guideline for tank volumes:
13 – 19 cu ft: pony bottle, redundant air source or used as a stage bottle
30 – 40 cu ft: stage bottle, redundant air source in overhead environments
50 – 63 cu ft: primary air source for a child or small adult
72 – 100 cu ft: primary air source for an adult
104 – 130 cu ft: primary air source for a large adult (also used in technical diving)
These are made using either aluminum or steel. Aluminum tanks are much more resistant to rust and start negatively buoyant. These tanks turn more positive as the air is consumed. Steel cylinders are the sturdier of the two materials and also start negatively buoyant. They either remain that way without air or turn towards a neutral buoyancy. This requires fewer weights to be carried.
The choice is between aluminum and steel. Aluminum cylinders are negatively buoyant at the start of your dive and positively buoyant near the end. This may sound like a good thing, but it can make stopping for safety checks harder as you will be naturally floating toward the surface of the water, and you may need weights to keep you down.
Steel cylinders stay negatively buoyant when you are in the water, so it is easier to control your depth. Steel tanks are also more durable than aluminum, but they are also heavier.
There are a few accessories that you can add to your scuba tank to protect it and to make it easier to use. A cylinder boot will give the bottom of your cylinder a flat surface to sit on and will ensure that it does not get any knocks or bumps from being knocked over. A mesh protector sleeve will protect the outside of the cylinder and will protect it from impacts.
Valve covers help to protect the weak point on your cylinder. They help to keep dirt and water out of your valves. They also protect the valves from damage; keeping the air contained. You can also add handles and carriers to your cylinder to help in the transport of your cylinders to and from the water.
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Low Or High Pressure
A high-pressure tank can hold more air. They allow for a higher capacity at a smaller size. The downside is that they are a lot heavier and harder to wield. They also have to be especially filled.
Even beginning divers need to look to the future. Diving Nitrox, compressed air with added oxygen, helps diver be safer or extend bottom times. However, Tanks need to be cleaned to Nitrox standards. The valve and the tank need to be compatible. Most new tanks are compatible with 40% but check to make sure.
Q: Dive Tank or Dive Cylinder?
You will see these items referred to as both dive tanks and dive cylinders. Technically, any device designed to hold compressed air is called a cylinder or vessel. A tank is a device to hold liquids or gas at ambient pressure. All official documentation and requirements apply to cylinders. Still, the word tank is often used and in the informal dive community, both words are used.
Q: Should I Buy My Tanks?
If you and your dive buddy just want to get up and go diving, then yes. It will be up to you to have them filled and ready. However, there are no restrictions on when you go. If you only dive on vacation or with a dive center, the answer is most likely no. There is little difference between the price of an air refill and a rental of a tank with air. Also, air travel requires that the valve be removed. So before you refill the tank it needs to be inspected.
Q: Should I Buy Steel Or Aluminum Dive Cylinders?
Steel cylinders are tougher than aluminum. They can take more impact while protecting the air inside. The downside of steel cylinders is that they are more expensive than aluminum. Both types will do the job for you, but you need to know where you are diving to make the best choice of the cylinder.
Steel cylinders are galvanized to prevent rusting and the toughness of the material allows them to withstand up to 300 bar of pressure. Aluminum cylinders will not add a lot of weight to your diving equipment, but they can only withstand up to 232 bar of pressure. You will often hear that steel tanks are heavier. A steel tank the same physical size as an aluminum tank will be heavier. However, it will hold more air.
Q: What Size Cylinder Do I Need?
There are a variety of sizes available, and the choice will come down to many actors. The more air you have available, the longer you will be able to dive, so if you are planning on being in the water for long periods, then you should go for a larger capacity. The downside of a large cylinder is that it is heavier. You should ensure that you can carry a large cylinder before you purchase one to dive with.
Q: Should I Buy A 232BAR Or 300BAR Cylinder?
Higher pressure means more volume inside your cylinder, but it also means a heavier cylinder. If you can get more air in, then there is more weight. Cylinders that can handle more pressure also have more material to do so. Both cylinders may look alike, but the 300 bar cylinder will have thicker walls so it will be heavier. If you are a recreational diver, you will not need the more expensive 300 bar cylinders.
Q: What Type Of Cylinder Valve Do I Need?
The type of valve you will need depends on the pressure of the tanks you use and to a lesser extent the location you dive. DIN valves are a European standard and can be used for 232 or 300 bar cylinders. A DIN valve is more secure and is favored by technical divers as well. An A-clamp valve, also called international or yoke, is used for recreational diving and will only work with 232 bar cylinders. Pro valves are relatively new, they provide both connections with the 232 bar tanks.
Related Post: What Is In A Scuba Tank
Q: Do I Need A Cylinder Boot?
A cylinder boot will give your cylinder something to stand on when you are not using it. It connects to the bottom of your cylinder and gives it a flat surface to rest on instead of a rounded one. You do not need a cylinder boot, but we would recommend having one to prevent your cylinder from knocks and bumps.
Q: How Many Tanks Do I Need?
You will need a tank for each dive. Most divers who own their tanks will have two or three. The number of dives they plan on doing until they refill the tanks.
Globo Surf Overview
Breathing underwater is an incredible feeling. Being able to comfortably explore the underwater world while not worrying about maintaining buoyancy is one of your top priorities when you are diving. A great air tank will give you this and more. There are many accessories and pieces of safety equipment that we would recommend for diving, but a top-rated cylinder is where it all starts.
Choosing a diving tank does not need to be stressful. If you take the time to understand exactly how diving talks work, then you can buy one with the peace of mind that you are buying something which will keep you alive under the water, and will not fail. Our list is packed with the best dive tanks on the market. There is something there for everyone.