Surface supply diving uses air from the surface to help 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 may differ slightly for surface supply divers, as well as those who are not certified to use scuba gear.
Diver's umbilical
The primary connection between the diver, the surface supply diving equipment and the umbilical of the Diver is through the umbilical. It is responsible for carrying the primary breathing gas from surface to diver's equipment. You can attach the umbilical directly to the diver or 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. The devices include a cable for communication, a thermometer, and a hot-water suit. These components enable divers to monitor depth and provide air in emergency situations.
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 realizes it or not, the air pressure can vary greatly during a dive. This can increase the effort required to breathe and may also affect the hydrostatic and cracking pressure. These changes will not reduce oxygen delivery to lungs. The pressure can increase the efficiency of the diver's breathing system in removing carbon dioxide. This improves their quality of breath.
Divers usually breathe from the demand valve, while the main air supply is controlled by a regulator. 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. When the diver breathes, the demand valve will supply gas to the remote mouthpiece at ambient pressure.
Saturation spread
The environment must be pressurized for surface supply diving. There are several ways to do this, including a saturation system or a "saturation spread." 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.
Most commonly, saturation diving is used offshore, near production platforms and drilling platforms, as well as in the contexts of salvage operations. For this type diving, you need to know where you are going and how you will position yourself. This can be done most often from a specially designed diving support vessel or another suitable vessel. However, dynamic positioning is essential and requires reliable equipment.
Diver's fitness to dive examination
Before diving in surface supply, divers must have a thorough fitness-todive examination. This is done by an AMED, which will examine any underlying medical conditions that could be a problem for their ability to dive. The examination can be valid for up 12 months and must always be renewed. The diver must also pass a fitness test at renewal.
The medical examination standards are specified by dive certification agencies. Some require an examination by a medical practitioner, while others make the exam entirely up to the examinee. These standards are almost always the same between different 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
The equipment used for surface supply diving is not very different from that used by deep divers. The primary difference is the breathing gas used. In surface supply diving the gas used is set at the gas panel. Accordingly, the tank pressure doesn't adjust with the dive depth. Some surface supply diving demand helmets have an extra feature called "dial-a breath" that allows the diver adjust the gas level in their tank.
Apart from the tank, divers will also require a set of voice communication equipment to communicate with the surface. These devices can be connected to the full-face helmet or mask by an umbilical cord. The cable should be checked for function and soundness before diving.