Depth gaugeA depth gauge is an instrument for measuring depth below a reference surface. They include depth gauges for underwater diving and similar applications, and engineering instruments used to measure the depth of holes and indentations from a reference surface. A diving depth gauge is a pressure gauge that displays the equivalent depth below the free surface in water. The relationship between depth and pressure is linear and accurate enough for most practical purposes, and for many purposes, such as diving, it is actually the pressure that is important.
Dive leaderDive leader is the title of an internationally recognised recreational diving certification. The training standard describes the minimum requirements for dive leader training and certification for recreational scuba divers in international standard ISO 24801-3 and the equivalent European Standard EN 14153-3. Various organizations offer training that meets the requirements of the dive leader standard.
Underwater photographyUnderwater photography is the process of taking photographs while under water. It is usually done while scuba diving, but can be done while diving on surface supply, snorkeling, swimming, from a submersible or remotely operated underwater vehicle, or from automated cameras lowered from the surface. Underwater photography can also be categorised as an art form and a method for recording data. Successful underwater imaging is usually done with specialized equipment and techniques.
Dive centerA dive center is the base location where recreational divers usually learn scuba diving or make guided dive trips at new locations. Many dive centers operate under the guidelines of ISO 24803, in which case the facilities must meet the ISO minimum standard for a service provider for recreational diving. Divers commonly refer to dive centers as dive shops. It is normally a shop selling diving equipment equipped with a diving air compressor to fill the cylinders. The dive center usually offers the facilities to repair and maintain scuba gear.
Dräger (company)Dräger is a German company based in Lübeck which makes breathing and protection equipment, gas detection and analysis systems, and noninvasive patient monitoring technologies. Customers include hospitals, fire departments and diving companies. The company was founded in Lübeck in 1889 as Dräger & Gerling by de and Carl Adolf Gerling. The first patent was taken out for a reduction device for using carbon dioxide to dispense beer. In 1902 Heinrich Dräger's son Bernhard entered the management; from then on, the company was named Drägerwerk Heinr.
Underwater searchesUnderwater searches are procedures to find a known or suspected target object or objects in a specified search area under water. They may be carried out underwater by divers, manned submersibles, remotely operated underwater vehicles, or autonomous underwater vehicles, or from the surface by other agents, including surface vessels, aircraft and cadaver dogs. A search method attempts to provide full coverage of the search area, and to do this a search pattern is usually applied, which is a systematic procedure for covering the search area.
Diver propulsion vehicleA diver propulsion vehicle (DPV), also known as an underwater propulsion vehicle, sea scooter, underwater scooter, or swimmer delivery vehicle (SDV) by armed forces, is an item of diving equipment used by scuba divers to increase range underwater. Range is restricted by the amount of breathing gas that can be carried, the rate at which that breathing gas is consumed, and the battery power of the DPV. Time limits imposed on the diver by decompression requirements may also limit safe range in practice.
Decompression theoryDecompression theory is the study and modelling of the transfer of the inert gas component of breathing gases from the gas in the lungs to the tissues and back during exposure to variations in ambient pressure. In the case of underwater diving and compressed air work, this mostly involves ambient pressures greater than the local surface pressure, but astronauts, high altitude mountaineers, and travellers in aircraft which are not pressurised to sea level pressure, are generally exposed to ambient pressures less than standard sea level atmospheric pressure.
Recreational dive sitesRecreational dive sites are specific places that recreational scuba divers go to enjoy the underwater environment or for training purposes. They include technical diving sites beyond the range generally accepted for recreational diving. In this context all diving done for recreational purposes is included. Professional diving tends to be done where the job is, and with the exception of diver training and leading groups of recreational divers, does not generally occur at specific sites chosen for their easy access, pleasant conditions or interesting features.
Scuba diving tourismScuba diving tourism is the industry based on servicing the requirements of recreational divers at destinations other than where they live. It includes aspects of training, equipment sales, rental and service, guided experiences and environmental tourism. Motivations to travel for scuba diving are complex and may vary considerably during the diver's development and experience. Participation can vary from once off to multiple dedicated trips per year over several decades.
