Underwater archaeology is archaeology practiced underwater. As with all other branches of archaeology, it evolved from its roots in pre-history and in the classical era to include sites from the historical and industrial eras. Its acceptance has been a relatively late development due to the difficulties of accessing and working underwater sites, and because the application of archaeology to underwater sites initially emerged from the skills and tools developed by shipwreck salvagers. As a result, underwater archaeology initially struggled to establish itself as actual archaeological research. This changed when universities began teaching the subject and a theoretical and practical base for the sub-discipline was firmly established in the late 1980s. Underwater archaeology now has a number of branches including, maritime archaeology: the scientifically based study of past human life, behaviours and cultures and their activities in, on, around and (lately) under the sea, estuaries and rivers. This is most often effected using the physical remains found in, around or under salt or fresh water or buried beneath water-logged sediment. In recent years, the study of submerged WWII sites and of submerged aircraft in the form of underwater aviation archaeology have also emerged as bona fide activity.
Wreck diving is recreational diving where the wreckage of ships, aircraft and other artificial structures are explored. The term is used mainly by recreational and technical divers. Professional divers, when diving on a shipwreck, generally refer to the specific task, such as salvage work, accident investigation or archaeological survey. Although most wreck dive sites are at shipwrecks, there is an increasing trend to scuttle retired ships to create artificial reef sites. Diving to crashed aircraft can also be considered wreck diving. The recreation of wreck diving makes no distinction as to how the vessel ended up on the bottom.
A remotely operated vehicle (ROV) is a free-swimming submersible craft used to perform tasks such as valve operations, hydraulic functions and other general tasks within the subsea oil and gas industry. ROVs can also carry tooling packages for undertaking specific tasks such as pull-in and connection of flexible flowlines and umbilicals, and component replacement.
Diving activities are the things people do while diving underwater. People may dive for various reasons, both personal and professional. While a newly qualified recreational diver may dive purely for the experience of diving, most divers have some additional reason for being underwater. Recreational diving is purely for enjoyment and has several specialisations and technical disciplines to provide more scope for varied activities for which specialist training can be offered, such as cave diving, wreck diving, ice diving and deep diving. Several underwater sports are available for exercise and competition.
Professional diving is underwater diving where the divers are paid for their work. The procedures are often regulated by legislation and codes of practice as it is an inherently hazardous occupation and the diver works as a member of a team. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-site hyperbaric chamber and diver-to-surface communication system is often required by law, and the mode of diving for some applications may be regulated.
Police diving is a branch of professional diving carried out by police services. Police divers are usually professional police officers, and may either be employed full-time as divers or as general water police officers, or be volunteers who usually serve in other units but are called in if their diving services are required.
Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface air supply, and therefore has a limited but variable endurance. The name "scuba", an acronym for "Self-Contained Underwater Breathing Apparatus", was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the likelihood and effects of nitrogen narcosis during deeper dives.
The archaeology of shipwrecks is the field of archaeology specialized most commonly in the study and exploration of shipwrecks. Its techniques combine those of archaeology with those of diving to become Underwater archaeology. However, shipwrecks are discovered on what have become terrestrial sites.
The Georgiana was a brig-rigged, iron hulled, propeller steamer belonging to the Confederate States Navy during the American Civil War. Reputedly intended to become the "most powerful" cruiser in the Confederate fleet once her guns were mounted, she was never used in battle. On her maiden voyage from Scotland, where she was built, she encountered Union Navy ships engaged in a blockade of Charleston, South Carolina, and was heavily damaged before being scuttled by her captain. The wreck was discovered in 1965 and lies in the shallow waters of Charleston's harbor.
Edward Lee Spence is a pioneer in underwater archaeology who studies shipwrecks and sunken treasure. He is also a published editor and author of non-fiction reference books; a magazine editor, and magazine publisher ; and a published photographer. Spence was twelve years old when he found his first five shipwrecks.
Scientific diving is the use of underwater diving techniques by scientists to perform work underwater in the direct pursuit of scientific knowledge. The legal definition of scientific diving varies by jurisdiction. Scientific divers are normally qualified scientists first and divers second, who use diving equipment and techniques as their way to get to the location of their fieldwork. The direct observation and manipulation of marine habitats afforded to scuba-equipped scientists have transformed the marine sciences generally, and marine biology and marine chemistry in particular. Underwater archeology and geology are other examples of sciences pursued underwater. Some scientific diving is carried out by universities in support of undergraduate or postgraduate research programs, and government bodies such as the United States Environmental Protection Agency and the UK Environment Agency carry out scientific diving to recover samples of water, marine organisms and sea, lake or riverbed material to examine for signs of pollution.
Mark M. Newell, Ph.D. RPA is a British/American underwater and terrestrial archaeologist and anthropologist, the director of the Georgia Archaeological Institute. He received his doctorate from St. Andrews University, Scotland. Newell began diving in Bermuda in 1963. While working as a journalist, he continued to dive throughout the Caribbean and South America, developing an interest in the archaeological potential of the sites he discovered. In 1996 he completed a Ph.D. in underwater archaeology at the Scottish Institute of Maritime Studies at the University of St. Andrews.
Agnes Milowka was an Australian technical diver, underwater photographer, author, maritime archaeologist and cave explorer. She gained international recognition for penetrating deeper than previous explorers into cave systems across Australia and Florida, and as a public speaker and author on the subjects of diving and maritime archaeology. She died aged 29 while diving in a confined space.
Dewey Dewayne Smith was an underwater diver, former United States Navy medic and professional aquanaut. He died during a dive from the Aquarius underwater habitat off Key Largo in May 2009. A subsequent investigation determined that multiple factors combined to cause the accident.
Nautilus Productions LLC is an American video production, stock footage, and photography company incorporated in Fayetteville, North Carolina in 1997. The principals are producer/director Rick Allen and photographer Cindy Burnham. Nautilus specializes in documentary production and underwater videography, and produced QAR DiveLive, a live webcast of underwater archaeology filmed at the wreck of the Queen Anne's Revenge in 2000 and 2001.
The history of scuba diving is closely linked with the history of the equipment. By the turn of the twentieth century, two basic architectures for underwater breathing apparatus had been pioneered; open-circuit surface supplied equipment where the diver's exhaled gas is vented directly into the water, and closed-circuit breathing apparatus where the diver's carbon dioxide is filtered from the exhaled breathing gas, which is then recirculated, and more gas added to replenish the oxygen content. Closed circuit equipment was more easily adapted to scuba in the absence of reliable, portable, and economical high pressure gas storage vessels. By the mid-twentieth century, high pressure cylinders were available and two systems for scuba had emerged: open-circuit scuba where the diver's exhaled breath is vented directly into the water, and closed-circuit scuba where the carbon dioxide is removed from the diver's exhaled breath which has oxygen added and is recirculated. Oxygen rebreathers are severely depth limited due to oxygen toxicity risk, which increases with depth, and the available systems for mixed gas rebreathers were fairly bulky and designed for use with diving helmets. The first commercially practical scuba rebreather was designed and built by the diving engineer Henry Fleuss in 1878, while working for Siebe Gorman in London. His self contained breathing apparatus consisted of a rubber mask connected to a breathing bag, with an estimated 50–60% oxygen supplied from a copper tank and carbon dioxide scrubbed by passing it through a bundle of rope yarn soaked in a solution of caustic potash. During the 1930s and all through World War II, the British, Italians and Germans developed and extensively used oxygen rebreathers to equip the first frogmen. In the U.S. Major Christian J. Lambertsen invented a free-swimming oxygen rebreather. In 1952 he patented a modification of his apparatus, this time named SCUBA, an acronym for "self-contained underwater breathing apparatus," which became the generic English word for autonomous breathing equipment for diving, and later for the activity using the equipment. After World War II, military frogmen continued to use rebreathers since they do not make bubbles which would give away the presence of the divers. The high percentage of oxygen used by these early rebreather systems limited the depth at which they could be used due to the risk of convulsions caused by acute oxygen toxicity.
The following outline is provided as an overview of and topical guide to underwater diving:
The following index is provided as an overview of and topical guide to underwater diving:
The Underwater Association (UA) was a research association focused on the conduct of research underwater by diving scientists and archaeologists. It was established by a group of UK scientists in Malta in 1966 to assist in the organisation and publication of British diving science. Membership grew to over 400, with approximately one third joining from outside the UK. From 1972 to 1979 the UA published a Code of Practice for scientific diving. This was expanded in 1987 and 1990 to form the UNESCO Code of practice. Membership declined in the late 1980s, and the UA merged with the Society for Underwater Technology in 1992.
