Surface supply diving refers to using surface air to assist the diver. It uses many of the same procedures as scuba diving. While many of the procedures are similar for all divers, some are specific to certain equipment or diving tasks. These procedures could be slightly different for beginners or for those who have never been certified for diving without scuba gear.
Diver's umbilical
The primary connection between a diver and his surface supply diving system, the Diver's umbilical. It is responsible for carrying the primary breathing gas from surface to diver's equipment. The umbilical can either be directly attached to the diver or attached via a bell panels.
The umbilical connects a diving mask to the surface, and it contains a variety of devices to help divers stay safe and comfortable in the water. These devices may include a communication cable, a pneumofathometer, and a hot water suit. Divers can monitor their depth and give air to help in an emergency.
Diver's demand-valve
The Diver's Demand Valve is designed to increase surface supply diving air pressure. This pressure can cause diver to breathe faster and deeper than without the demand valve. The pressure of the air can fluctuate during diving, regardless of whether the diver is aware. This can increase work and cause cracking and hydrostatic pressure to rise. These changes do not affect the oxygen supply to the lungs. By increasing the pressure, the diver's respiratory system can be more efficient at removing carbon dioxide from the air, and this improves the quality of their breathing.
Divers breathe normally from the demand valve, while the main air supply to the regulator is controlled. The regulator is usually fitted with a single hose and is held by the diver's mouthpiece. If the diver is using a dual-hose regulator the demand valve is located inside the regulator. It attaches to either the cylinder valve outlet or the manifold outlet. The demand valve will provide gas to the remote airway at ambient pressure when the diver breathes.
Saturation spread
A pressurized environment is required for surface supply diving. This can be done in a variety of ways, including a saturation spread or a saturation system. Saturation diving involves diving under the pressure of a saturation accommodation. The divers then return to the surface with a mixture made up of helium and oxygen.
The majority of saturation diving is done offshore, on drilling platforms or near production, and when there are salvage operations. To perform this type of dive, it is important to have precise positioning during the dive. This is usually done using a special diving support vessel or other suitable vessel. While dynamic positioning is very important, it requires a reliable system.
Diver's fitness-to dive exam
A comprehensive fitness-to dive examination must be completed before a diver can participate in surface supply diving. The AMED, a medical examiner for divers, will perform the examination. This will determine if there are any conditions that could affect their diving ability. The certification is valid for a maximum of 12 months. It must be renewed every year. At the time of renewal, the diver will also have to take a fitness test.
Dive certification organizations specify the standards of medical examination. Some agencies require that a physician examine the diver, while others view the examination as largely a personal responsibility. These standards are typically similar across agencies. These standards are often based on the standards for professional divers. However, they may be slightly relaxed to decrease the incidence of diving-related medical conditions.
Diver's equipment
Surface supply diving equipment doesn't differ much from deep diving equipment. The only difference is the use of breathing gas. In surface supply diving the gas used is set at the gas panel. Because of this, the tank's pressure is not adjusted automatically when the depth drops. Some surface supply diving demand helmets might have an additional feature called a "dial a breath" system. This allows the diver the ability to adjust the tank's gas level.
Divers also require a set if voice communication devices to communicate with the surfaces. These devices connect to the mask or helmet of the diver using an umbilical wire. The cable should be checked for function and soundness before diving.