Surface supply diving uses air from the surface to help the diver. The standard procedures for surface supply diving are very similar to those used in 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 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 diver's umbilical and the surface supply diving system is the Diver's Umbilical. It carries primary breathing gas from the surface down to the diver's device. The umbilical can either be directly attached to the diver or attached via a bell panels.
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. The devices include a cable for communication, a thermometer, and a hot-water suit. These components allow divers to monitor their depths and supply additional air in an emergency.
Diver's demand-valve
The Diver's demand valve is designed to increase the pressure of the air used during surface supply diving. The demand valve allows a diver's breathing to be more controlled and slow than it would without it. Whether the diver is conscious or not, the pressure of the air can vary considerably during a dive. This can increase the effort required to breathe and may also affect the hydrostatic and cracking pressure. These changes do not affect the oxygen supply to the lungs. By raising the pressure, the diver can make their respiratory system more efficient in removing carbon dioxide. This improves the quality of their respiration.
Divers typically inhale through the demand valve. A regulator controls the main supply of air. The regulator is usually fitted with a single hose and is held by the diver's mouthpiece. If the diver uses dual-hose regulators, the demand valve will be located in the regulator's body. This attaches directly to the cylinder or manifold outlets. The demand valve supplies gas at ambient pressure to the remote mouthpiece when the diver inhales.
Saturation spread
You need to dive in a pressurized environment for surface supply. You have two options: a saturation system, or a "saturation spreading". Saturation dive is when divers are put under pressure by a saturation accommodation and then returned to the surface using a helium-based gas mixture.
Saturation diving is most commonly used offshore, near production and drilling platforms, and in the context of salvage operations. To perform this type of dive, it is important to have precise positioning during the dive. This can usually be done from a specialist diving support vessel or any other vessel that is suitable. It is important to have reliable systems for dynamic positioning.
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 certification is valid for a maximum of 12 months. It must be renewed every year. The diver must also pass a fitness test at renewal.
The dive certification agencies set the standards for medical examination. Some require a medical practitioner's examination, while others consider the exam largely an individual responsibility. These standards are typically similar across agencies. These standards are usually based on standards for professional divers. They may be slightly modified to reduce the risk of diving-related injuries.
Diver's equipment
Surface supply diving equipment doesn't differ much from deep diving equipment. The main difference is in the type of breathing gas used. In surface supply diving the gas used is set at the gas panel. The tank's pressure does not adjust automatically as the water level 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 need to have a set voice communication devices in order to communicate with the surface. An umbilical cable connects these devices to the helmet or full-face mask of the diver. The cable should be checked for function and soundness before diving.