Maritime archaeologyMaritime archaeology (also known as marine archaeology) is a discipline within archaeology as a whole that specifically studies human interaction with the sea, lakes and rivers through the study of associated physical remains, be they vessels, shore-side facilities, port-related structures, cargoes, human remains and submerged landscapes. A specialty within maritime archaeology is nautical archaeology, which studies ship construction and use. As with archaeology as a whole, maritime archaeology can be practised within the historical, industrial, or prehistoric periods.
Underwater divingUnderwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving.
Scuba divingScuba 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.
ShipwreckA shipwreck is the wreckage of a ship that is located either beached on land or sunken to the bottom of a body of water. Shipwrecking may be intentional or unintentional. There were approximately three million shipwrecks worldwide as of January 1999, according to Angela Croome, a science writer and author who specialized in the history of underwater archaeology (an estimate rapidly endorsed by UNESCO and other organizations). When a ship's crew has died or abandoned the ship, and the ship has remained adrift but unsunk, they are instead referred to as ghost ships.
BuoyA buoy (ˈbuː.i,_bɔɪ) is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. Race course marker buoys are used for buoy racing, the most prevalent form of yacht racing and power boat racing. They delimit the course and must be passed to a specified side. They are also used in underwater orienteering competitions. Emergency wreck buoys provide a clear and unambiguous means of temporarily marking new wrecks, typically for the first 24–72 hours.
Recreational divingRecreational diving or sport diving is diving for the purpose of leisure and enjoyment, usually when using scuba equipment. The term "recreational diving" may also be used in contradistinction to "technical diving", a more demanding aspect of recreational diving which requires more training and experience to develop the competence to reliably manage more complex equipment in the more hazardous conditions associated with the disciplines.
