Surface supply diving uses air from the surface to help the diver. Many of the standard procedures are identical to scuba diving. Many of these procedures can be used for all divers. Some are more specific to 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 the diving system and the diver is the umbilical. It carries the primary breath gas from the surface to your apparatus. It can be connected directly to the diver, or via a bell-panel attachment.
The umbilical connects to a diving mask to surface. It has a variety devices that assist divers in staying safe and comfortable in the sea. Some of these devices could include a communications cable, a pneumofathometer and a hot water suit. This allows divers to keep track of their depths, and also provides additional air for emergency situations.
Diver's demand valve
The Diver's Demand Valve is designed to increase surface supply diving air pressure. This pressure can cause divers to breath slower and deeper than they would without the demand valve. The pressure of the air can fluctuate during diving, regardless of whether the diver is aware. This can increase the work required to breathe, and also the cracking pressure and hydrostatic pressure. 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 usually breathe from the demand valve, while the main air supply is controlled by a regulator. The regulator is typically fitted with one hose and held in place by the diver's mouthpiece. The demand valve, which attaches either to the manifold outlet or cylinder valve, is found in the regulator's body if the diver uses a dual hose regulator. The demand valve is activated when the diver breathes. It will provide gas to remote mouthpiece at ambient temperature.
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 allows divers to dive under pressure. They are then able to return to the surface and inhale a mixture of helium, helium, or both.
Saturation diving is most commonly used offshore, near production and drilling platforms, and in the context of salvage operations. For this type diving, you need to know where you are going and how you will position yourself. This can often be done from a specialized diving support vessel (or a vessel suitable for the occasion). Dynamic positioning is also important, but 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. An AMED (diver's medical examiner) will perform this exam. They will also assess any other health conditions that may pose a threat to their diving abilities. The annual renewal is required. The diver will need to pass a fitness exam at renewal.
The dive certification agencies set the standards for medical examination. Some agencies require a medical practitioner to perform the exam, while others leave it up to the individual to do the exam. These standards are almost always the same between different agencies. Often, these standards are based on those for professional divers, but may be relaxed slightly in order to reduce the incidence of diving-related medical conditions.
Diver's equipment
Surface supply diving equipment is very similar to deep diving equipment. The main difference is in the type of breathing gas used. The gas panel is used to control the gas flow. Accordingly, the tank pressure doesn't adjust with the dive depth. Some surface supply diving demand Helms may have an additional feature called a “dial-a–breath” system which allows the diver or divers to adjust the level of gas in their tank.
For communication with the surface, divers need more than a tank. 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.