Apart from the necessary clothing you will also need some extra diving equipment before entering the water.
The Buoyancy Compensation Device:
The buoyancy compensation device (BCD) is required to maintain your buoyancy underwater. There are different types of devices. It is worn like a jacket and consists of the following:
Internal air bladders
A hose for adding and extracting air from bladders
A loop system for holding air cylinder
Pockets and D-rings for equipment
Air is added or extracted out of internal bladders.
The human body is designed to be naturally buoyant and although it might be carrying heavy diving equipment like a cylinder it will not automatically sink. To counteract this natural buoyancy divers need to wear lead weights placed either on a belt, inside a harness or in the pockets of the BCD.
To control the balance of buoyancy air is added to the BCD to keep the diver off the bottom of the dive location or in the depth chosen. When on the surface, the BCD is filled with air to counteract the negative effects of the weights.
Contrary to what most people believe, cylinders do not contain oxygen. They contain air. The air in the cylinder is compressed under pressure. It is measured either in pounds per square inch (psi) or measured by bar. This is controlled by a valve on the top of the cylinder.
Cylinders come in a range of sizes measured in cubic feet or liters. They are usually constructed of steel or aluminum. Different sizes of cylinders have their advantages and disadvantages. Larger ones will allow the diver to remain under water for longer periods but the disadvantage is they are heavier to carry.
All cylinders need to be inspected regularly. These diving equipment items should be tested periodically by accredited testing facilities to check they are safe to use.
Regulators are diving equipment required to control the air in the cylinder because the air in a cylinder is held at very high pressure. Humans would not be able to breathe it. Therefore, regulators are required to adjust the pressure to a level that a human being can breathe.
There are a series of high pressure hoses:
1. Feed for the BCD
2. Accommodate the mouthpiece (the demand valve)
3. Alternative air source (known as octopus)
4. Contain the gauge.
The demand valve (DV) will deliver breathable air to the diver by way of the mouthpiece. The diver breathes in and out with the air being expelled through an exhaust on the DV.
The octopus is the second demand valve which will be used by a buddy in case of emergencies. It is colored bright yellow for easy identification underwater.
The contents gauge will keep the diver informed of the available air in the cylinder.
The computer is worn on the wrist to record:
Length of time underwater
Rate of ascent to the surface
Calculate compression stops
Clothing required are: Mask, fins and protective clothing – skin suit, wet suit, semi dry suit and/or a dry suit.
Being properly equipped ensures your safety. Always check diving equipment with your buddy before attempting any dive.