Surface supply diving uses air from the surface to help the diver. It uses many of the same procedures as scuba diving. These procedures are generally the same for all divers. However, some of them are tailored to specific equipment or diving tasks. These procedures can be slightly different for new divers or those who have never dived without scuba equipment.
Diver's umbilical
The primary connection between the diving system and the diver is the umbilical. It is responsible for carrying the primary breathing gas from surface to diver's equipment. The umbilical can be either directly attached to the diver, or it can be attached via a bell panel.
The umbilical connects the diving mask to the surface and contains many devices that help divers remain safe and comfortable in water. This could include a communication cable or a pneumofathometer. Divers can monitor their depth and give air to help in an emergency.
Diver's demand valve
The Diver’s demand Valve is designed for increasing the pressure of air used in surface supply diving. This pressure can cause diver to breathe faster and deeper than without the demand valve. Regardless of whether the diver is conscious, the pressure in the air can change significantly during a dive. This can increase both the work of breathing and the hydrostatic pressure. These changes do not affect the oxygen supply to the lungs. By raising the pressure, divers' respiratory systems can remove more carbon dioxide from the atmosphere, which improves the quality and quantity of their breathing.
Divers typically inhale through the demand valve. A regulator controls the main supply of air. The regulator is typically fitted with one hose and held in place by the diver's mouthpiece. If the diver uses a dual-hose regulator, the demand valve is located in the body of the regulator, which attaches to the cylinder valve or manifold outlet. 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. You can do this in several ways. Saturation diving refers to diving where divers are placed under pressure using a saturation accommodation system and then return to the surface by inhaling a mixture of helium and gas.
Saturation diving is most commonly used offshore, near production and drilling platforms, and in the context of salvage operations. This type of dive requires precise positioning. This can usually be done from a specialist diving support vessel or any other vessel that is suitable. Dynamic positioning is also important, but requires a reliable system.
Diver's fitness-to-dive examination
Before participating in surface supply diving, divers must undergo a comprehensive fitness-to-dive examination. 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 examination is valid for up to 12 months and must be renewed annually. At the time of renewal, the diver will also have to take a fitness test.
The dive certification agencies set the standards for medical examination. While some require the medical practitioner to conduct an examination, others see it as largely the responsibility of the individual. These standards can be shared between agencies, but they are often similar. These standards are often based upon those for professional divers. However they can be adjusted slightly to decrease the likelihood of diving-related medical problems.
Diver's equipment
Surface supply diving equipment is very similar to deep diving equipment. The primary difference is the breathing gas used. In surface supply diving the gas used is set at the gas panel. As a result, the pressure of the air in the tank does not automatically adjust as the depth decreases. 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.
Apart from the tank, divers will also require a set of voice communication equipment to communicate with the surface. These devices are connected to the diver's full-face mask or helmet by an umbilical cable. Before diving, ensure that the cable is in good condition.