There are many different diving cylinders available on the market from a range of different manufacturers. The first thing to decide is the size of cylinder. Choosing a cylinder will depend on the type of activity you have planned, how deep you want to dive and for how long you plan to stay underwater. Your physical strength is another major factor as heavier cylinders will require more strength to manoeuvre in and out of the water. Diving cylinders typically range in capacity from 3-15 litres with varying weights.
The next decision to make is the material. Diving cylinders are either made of steel or aluminium and each material has several defining characteristics.
Steel is tougher than aluminium which means that steel diving cylinders are structurally much tougher and harder wearing in composition. To keep them in the best condition and to prevent rust they need to be painted and stored in dry conditions when not in use. Steel diving cylinders can hold more air than aluminium cylinders and due to their composition can also keep air at a higher pressure.
Aluminium diving cylinders are generally speaking not as tough or durable as steel cylinders due to the properties of aluminium itself. Because of this aluminium diving cylinders are thicker and heavier than steel cylinders which may make them less appealing to some divers. Aluminium cylinders are less resistant to corrosion compared to steel but are not susceptible to rust which can affect steel cylinders inside and out.
Taking care of your diving cylinder is important as it is an essential piece of kit when diving. Cylinder boots are recommended for protecting steel cylinders from knocks and bumps during transit and to keep them standing upright. Due to their construction and composition aluminium cylinders do not require a cylinder boot.