<P> Maritime archaeology or marine archaeology is the study of material remains of ancient peoples . A specialized branch, Archaeology of shipwrecks studies the salvaged artifacts of ancient ships . Stone anchors, amphorae shards, elephant tusks, hippopotamus teeth, ceramic pottery, a rare wood mast and lead ingots are examples which may survive the test of time for archaeologists to study and place the salvaged findings into a time line of history . coral reefs, tsunamis, cyclones, mangrove swamps, battles and a criss cross of sea routes in a high trading area combined with pirating have all contributed to shipwrecks in the Bay of Bengal . </P> <Ul> <Li> 1778 to 1783 The Naval operations in the American Revolutionary War or American War of Independence ranged as far as the Bay of Bengal . </Li> <Li> c. 1816 Mornington ship burned in the Bay of Bengal . </Li> <Li> 1850 American clipper brig Eagle is supposed to have sunk in the Bay of Bengal . </Li> <Li> American Baptist missionary Adoniram Judson, Jr. died 12 April 1850 and was buried at sea in the Bay of Bengal . </Li> <Li> 1855 The Bark "Incredible" struck on a sunken rock in the Bay of Bengal . </Li> <Li> 1865, a gale dismasted the Euterpe while traversing the Bay of Bengal typhoon . </Li> <Li> 1875 Veleda 76 m (250 ft) long and 15 m (50 ft) wide is a part of a current salvage operation . </Li> <Li> 1942 Japanese cruiser Yura of the Second Expeditionary Fleet, Malay Force, attacked merchant ships in the Bay of Bengal . </Li> <Li> 1971 December 3--It was claimed that the Indian Navy destroyer, INS Rajput, sunk the Pakistan Navy submarine PNS Ghazi off Visakhapatnam, in the Bay of Bengal . </Li> </Ul> <Li> 1778 to 1783 The Naval operations in the American Revolutionary War or American War of Independence ranged as far as the Bay of Bengal . </Li> <Li> c. 1816 Mornington ship burned in the Bay of Bengal . </Li>

How many states of india have a coastline along the bay of bengal