SCUBA Equipment

Divers need to carry a wide range of equipment. This can vary, depending upon the type of dive being carried out.

This section provides a brief look at the SCUBA equipment used on every dive.

Buoyancy Compensator

Buoyancy compensator (BC) or "Stab Jacket".

Divers wear this piece of kit to carry the air cylinder and it is used to provide buoyancy at the surface and while under the water.

The BC can also be used as a life jacket to lift a diver to the surface in the event of an emergency ascent.

Pockets built into the BC can be used to carry additional items of kit, such as torches and decompression tables.

Cylinders

Cylinders are used to carry the divers air supply.

Diving cylinders are usually made from steel and range from approximately 7 litres to 18 litres capacity.

When full, air in the cylinder is 200-300 times the pressure of the atmosphere and the amount of air available for the diver is around 1400 litres - 5000 litres, depending up on the size of the cylinder.

The cylinder is usually re-filled after every dive and have to be tested and inspected regularly.

Regulator

The regulator is fitted directly to the dive cylinder. It reduces the pressure of the air in the cylinder to a pressure required for the diver to breathe.

The regulator provides air on demand. i.e. it only supplies air when the diver breathes in.

Air bubbles exit from the exhaust valve when the diver breathes out.

Other hoses can be fitted to the first stage of the regulator which provide additional functions for the diver's equipment. These allow the diver to monitor the pressure of the air in the cylinder, alternative air supplies for emergency ascents and direct feed supplies to dry suits and buoyancy compensators.

Dry Suit

When diving in the cooler waters of the UK, many divers choose to wear a dry suit.

There are various different types of materials available but the basic function of a dry suit is to keep the diver dry and warm. A second "undersuit" provides additional insulation and keeps the diver warm, while the dry suit keeps the diver dry with seals around the neck and wrists. The boots are part of the suit and entry is via a zip which provides a watertight seal when closed.

A pair of gloves and a hood are also required.

Air becomes trapped inside and either compresses or expands as the diver changes depth under water. This affects the divers buoyancy.

Additional air can be pumped into the suit via a hose on the regulator as the diver goes deeper. As the diver begins to surface, any air inside the suit begins to expand. This can be vented through an exhaust valve in the suit.

The diver also uses the drysuit to control buoyancy during a dive. Additional training is required before diving with a drysuit.

Dive Computer

Dive computers are used by most divers. The computer enables a diver to monitor depth, time and decompression throughout the duration of a dive.

The computer displays information about the current dive including the maximum depth reached, current depth, dive duration, time remaining and water temperature.

Some computers will even display information about the divers air supply and will calculate the remaining dive time based on the divers breathing rate.

Some computers can even be set to work with different breathing gas mixtures.

Dive data can be loaded to a PC after a dive.