Professional diving

Professional Diving is a type of diving where the divers are paid for their work. There are several branches of professional diving, the most well known of which is probably commercial diving. Any person wishing to become a professional diver normally requires specific training that satisfies legislation, such as that set by the United Kingdom Health and Safety Executive. Due to the dangerous nature of some professional diving disciplines, specialized equipment such as a diver to surface communication system is often required by law.

Diver with KB Bandmask [1]

Equipment

US Navy Diver using Kirby Morgan diving helmet

Diving suit

Depending on the water temperature and length of dive, the diver will either use a wetsuit, where neoprene provides thermal insulation but the diver gets wet, a hot water diving suit which is similar to a wetsuit but is flooded with warm water from the surface through an umbilical, or a drysuit, which keeps the diver totally dry and relies on either the suit material or the air trapped in thermal undergarments to insulate the diver. Certain applications require a specific type of dive suit; long dives into deep, cold water normally require a hot water suit, whilst diving into potentially contaminated environments requires a drysuit.^[1]

Breathing apparatus

A number of factors dictate the type of breathing apparatus used by the diver. Typical considerations include the length of the dive, water contamination, space constraints and vehicle access for support vehicles. Some disciplines will very rarely use surface supplied diving, such as military clearance divers, whilst commercial divers will rarely use SCUBA equipment.

Scuba

SCUBA equipment is normally used by media and military divers, often utilizing specialized equipment such as rebreathers, which are closed circuit SCUBA equipment that recycles breathing gas instead of releasing it into the water. It is the "re-breathing" of gas that makes rebreathers ideal for long duration dives, efficient decompression when the gas mix is adjustable, and for the observation of animals in the wild due to the lack of noisy bubbles. These characteristics also make rebreathers ideal for military use, such as when military divers are engaged in covert action or when performing mine clearance where bubbles could potentially set off an explosion.

Open circuit scuba equipment is occasionally used by commercial divers working on sites where surface supplied equipment is unsuitable, such as around raised structures like a water tower, or in remote locations where it is necessary to carry equipment to the dive site. Normally, for comfort and for practicality, a full face mask such as those manufactured by Kirby Morgan will be used to allow torches and video cameras to be mounted onto the mask. The benefit of full-face masks is that they can normally be used with surface supplied equipment as well, removing the need for the diver or the company to have two sets of expensive equipment.

Surface supplied

Surface-supplied divers from 1873 (Illustrated London News, February 8th)

This is, perhaps, the most common type of equipment used in professional diving, and the one most recognised by the public, made familiar through films such as The Abyss.

US Navy tender with umbilical - A typical surface supplied diving situation

Surface Supplied equipment can be used with full face masks or diving helmets. Helmets are normally to be found fitted with diver to surface communication equipment, and often with light sources and video equipment. The use of a full-face mask or a full diving helmet is down to requirements and personal preference, however the impact protection and warmth offered by a full diving helmet makes it popular for underwater construction sites and cold water work.

Breathing gas for the diver is piped down from the surface, through a long, flexible hose, called an umbilical. In addition to breathing gas, the umbilical may have additional hoses and cables for such things as communications equipment or hot water should the diver be using a hot water suit. The diver's breathing gas can is pumped down from either high pressure tanks or through a gas compressor.

If the diver is to be working at extreme depths for a long period, the diver may live in a special underwater habitat called a diving chamber. This type of surface supplied diving is known as saturation diving. The same technique for supplying breathing gas as regular surface supplied diving is used, with the diving bell receiving breathing gas and electricity from a diving support vessel on the surface. Due to the often extreme depths the diver is working at, specialised helium-based breathing gas mixtures are often used to prevent both nitrogen narcosis and oxygen toxicity which occurs at these extreme depths.

Branches of professional diving

Commercial diving

Offshore diving

Offshore diving is the most well known branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry in places such as the Gulf of Mexico in the United States and the North Sea in the United Kingdom and Norway. The work in this area of the industry typically revolves around the maintenance of oil platforms and the building of underwater structures used in the production process.

For many newly qualified divers, this is the entry point to the industry, the lack of experienced divers and the excess of qualified divers within the industry push down wages for younger, less experienced divers beginning their careers. The low wages, relative inexperience of the workforce combined with difficult and dangerous operating conditions make offshore diving the most dangerous area of employment for professional divers.

Equipment used for offshore diving tends to be surface supplied equipment but this does vary depending on the nature of the work and location, for instance Gulf of Mexico based divers may use wetsuits whilst North Sea divers need drysuits or even hot water suits due to the temperature of the water.

Inland / onshore diving

Inland or onshore diving is very similar to offshore diving in terms of the nature of work and the equipment used, the work often being in support of land based civil engineering projects, with the majority of the work either underwater survey or engineering work. The number of dive sites this covers is varied however, and divers can be found working in harbours and lakes, in rivers and around bridges and pontoons, with the bulk of this work being undertaken in freshwater. Onshore divers typically earn less per hour than their colleagues who work offshore, but the ability to work from home for many divers is an advantage.

The equipment used does depend on the nature of the work and location, but normally a mixture of SCUBA and Surface supplied diving equipment is used by divers and their employers.