Underwater archaeology is the study of human life, cultures and behaviours in ancient times by the artefacts found in fresh or salt water or beneath water-logged sediment. (crystalinks.com) Underwater archaeologists excavate shipwrecks, plane wrecks, what is left of structures, sunken cities, (crystalinks.com) bogs and wells in order to discover lost artefacts. (acuaonline.org) Underwater archaeology gives archaeologists a realistic story about the past, because when the ship, plane, city, etcetera gets buried under the waves, the objects remain roughly in the same place, creating an accidental time capsule of that moment. (crystalinks.com) Materials such as leather, fabric, wood and plants are preserved differently when they are underwater which can inform us about that civilisations culture, craft and lifestyle. (crystalinks.com).
To conduct an underwater excavation first the underwater archaeologists need to locate the site by searching through historical records, being told by divers, fisherman or locals who may have accidentally discovered a site (waterencyclopedia.com) or scan side-sonar and magnetometry can also be used to locate the site (crystalinks.com). A GPS can be used to arrive at the location and if the site is accessible by humans, scuba gear is required (waterencyclopedia.com). However, if the site is inaccessible or not safe for the divers, remotely operated vehicles or ROV, which are controlled from the boat, are sent down to film the site. (crystalinks.com) If the divers are sent down, they may discover that the artefacts are covered by sediments, so hoses connected to the research ship can be used to suction up these sediments. Gridding, which was originally a land archaeology technique, can be conducted underwater and the artefacts can also be numbered to help the divers to excavate (waterencyclopedia.com). After recording, mapping, drawing and photographing the site, the objects can be removed by using air bags that are attached to baskets (waterencyclopedia.com) however, sites are only excavated if it is under threat or if it will help answer important questions about the past. (aima.iinet.net) As the artefacts found at the underwater sites are usually accurate and well preserved it gives underwater archaeologists a better understanding on the ancient civilisation’s religious beliefs and behaviours, including exploration, lifestyle and military contests.
