Surface supply diving uses air from the surface to help the diver. There are many procedures that can be used to supply air from the surface, which is similar to scuba diving. Many of these procedures are the same for all divers, but some are unique to specific equipment and diving tasks. These procedures can be slightly different for new divers or those who have never dived without scuba equipment.
Diver's umbilical
The Diver's umbilical is the primary connection between the diver and the surface supply diving system. 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 to a diving mask to surface. It has a variety devices that assist divers in staying safe and comfortable in the sea. Some of these devices could include a communications cable, a pneumofathometer and a hot water suit. These components allow divers to monitor their depths and supply additional air in an emergency.
Diver's demand valle
The Diver's demand valve is designed to increase the pressure of the air used during surface supply diving. This pressure can cause diver to breathe faster and deeper than without the demand valve. The air pressure can vary a lot during diving, whether the diver is aware of it or not. This can increase the work of breathing, as well as the hydrostatic pressure 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 attached to the diver's mouthpiece and fitted with a single-hose hose. If the diver uses an dual-hose regulator, then the demand valve is attached to the cylinder outlet. The demand valve will provide gas to the remote airway at ambient pressure when the diver breathes.
Saturation spread
It is necessary to have a pressure environment in order to surface supply dive. There are two ways to achieve this: a saturation set 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.
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 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 for diving
A comprehensive fitness-to dive examination must be completed before a diver can participate in surface supply diving. This examination is performed by a diver's medical examiner (AMED), who will assess any underlying health conditions that might pose a risk to their diving ability. 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.
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. These standards are almost always the same between different agencies. 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
Surface supply diving equipment is very similar to deep diving equipment. The main difference is in the type of breathing gas used. The gas panel determines the gas that is supplied for surface supply diving. Because of this, the tank's pressure is not adjusted automatically when the depth drops. 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. An umbilical cable connects these devices to the helmet or full-face mask of the diver. Before diving, it is important to verify the sound quality and functionality of the cable.