Surface supply diving is when air is used to aid the diver. It uses many of the same procedures as scuba diving. Although many of these procedures can be used by all divers, others are only applicable to certain equipment and dive 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 the primary oxygen from the surface to the divers' apparatus. It can be connected directly to the diver, or via a bell-panel attachment.
The umbilical connects diving mask to the top and includes a number of devices to ensure divers are comfortable and safe. These devices can include a communication cord, a pumpofathometer, or a hot watersuit. Divers can monitor their depth and give air to help in an emergency.
Diver's demand valve
The Diver's demand valve increases the pressure of surface supply diving air. The demand valve allows a diver's breathing to be more controlled and slow than it would without it. The air pressure can vary a lot during diving, whether the diver is aware of it or not. This can increase both the work of breathing and the hydrostatic pressure. However, these changes do not impair the oxygen delivery 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 breathe normally from the demand valve, while the main air supply to the regulator is controlled. The regulator is usually attached to the diver's mouthpiece and fitted with a single-hose hose. 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 will provide gas to the remote airway at ambient pressure when the diver breathes.
Saturation spread
You need to dive in a pressurized environment for surface supply. There are several ways to do this, including a saturation system or a "saturation spread." Saturation diving involves diving under the pressure of a saturation accommodation. The divers then return to the surface with a mixture made up of helium and oxygen.
Saturation diving is most commonly used offshore, near production and drilling platforms, and in the context of salvage operations. You must be precise in your positioning to perform this type dive. 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 for diving
Before surface supply diving, all divers must complete a fitness-to–dive evaluation. A diver's medical examiner will conduct this examination. He or she will evaluate any health conditions that could pose a danger to their ability to dive. The certification is valid for a maximum of 12 months. It must be renewed every year. The diver will need to pass a fitness exam at renewal.
Dive certification agencies specify the medical exam standards. Some agencies require a medical practitioner to perform the exam, while others leave it up to the individual to do the exam. The standards vary between agencies but are generally the same. 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
Equipment used for surface supply diving does not differ from equipment used by deep divers. The only difference is the use of breathing gas. The gas panel controls the gas supply for surface supply diving. Accordingly, the tank pressure doesn't adjust with the dive 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.
Aside from the tank, divers also need a set of voice communication devices for communication with the surface. These devices can be connected to the full-face helmet or mask by an umbilical cord. Before diving, ensure that the cable is in good condition.