Surface supply diving refers to using surface air to assist the diver. The standard procedures for surface supply diving are very similar to those used in scuba diving. Many of these procedures are the same for all divers, but some are unique to specific equipment and diving tasks. For those new to surface supply diving, or who have never been certified to dive without their scuba gear, these procedures might be slightly different.
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 carries primary breathing gas from the surface down to the diver's device. It can be attached directly to the diver's apparatus or through a bell panel.
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. The devices include a cable for communication, a thermometer, and a hot-water suit. All of these components make it possible for divers to monitor their depth and provide additional air in case of an emergency.
Diver's demand lever
The Diver's demand valve is designed to increase the pressure of the air used during surface supply diving. The demand valve can make a diver breathe slower and deeper than normal. Regardless of whether the diver is conscious, the pressure in the air can change significantly 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. The pressure can increase the efficiency of the diver's breathing system in removing carbon dioxide. This improves their quality of breath.
Divers normally inhale via the demand valve. However, the regulator controls the main air supply. 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 is activated when the diver breathes. It will provide gas to remote mouthpiece at ambient temperature.
Saturation spread
It is necessary to have a pressure environment in order to surface supply dive. This can be done in a variety of ways, including a saturation spread or a saturation system. 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 can be used most often offshore, near production or drilling platforms, and within the context of salvage operations. You must be precise in your positioning to perform this type dive. 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. 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 annual renewal is required. A fitness test will be required at the renewal.
Dive certification agencies specify the medical exam standards. 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 often reflect those of professional divers. However these standards may be slightly relaxed to reduce the incidences of diving-related conditions.
Diver's equipment
Equipment used for surface supply diving does not differ from equipment used by deep divers. The major difference is the gas used. The gas panel determines the gas that is supplied for surface supply diving. Therefore, the pressure in the tank doesn't automatically decrease with depth. 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. These devices are connected by an umbilical cables to the diver's helmet or full-face face mask. Before diving, ensure that the cable is in good condition.