What sort of special equipment do marine archaeologists use?
The boats have to be supplied with underwater camera equipment. High pressure water jets are sometimes needed to dislodge the martial on the ocean floor. Arrangements have to be made to carefully lift things out of the water if necessary. The divers need to be provided with divine gear and air and oxygen cylinders. Underwater scooters are also a big help because the archaeologists can zoom along on them instead of tiring themselves out swimming ground the site. Different kinds of scientific instruments are also used. An echo sounding system registers a rise whenever the boat passes over an underwater object. A side scan electronic system gives a view of the sea floor. Underwater metal detectors held by divers give a signal if they sense any kind of metal object between 3-4 m away. At Dwarka, marine archaeologists surveyed a large area covered by 3-12 meters of water. They discovered the remains of a submerged port-city that may be as old as about 1500 B.C. The city seems to have been a
