Bodies of water, fresh and saline, have been important sources of food for people for as long as we have existed. It should be no surprise that ancient villages weree located at the water's edge. Since the last ice age sea level has risen as much as 250 feet (approximately 75 meters). Therefore, a great deal of the record of human activity throughout the Ice Age is now to be found under water.
The flooding of the area now known as the Black Sea (when a land bridge, where the Bosporus is now, collapsed under the pressure of rising water in the Mediterranean Sea) submerged a great deal of human activity that had been gathered round what had been an enormous, fresh-water lake.
Significant cave art sites off the coast of western Europe are now reachable only by diving, because the cave entrances are underwater, though the caves themselves are not flooded.
Technology is opening new areas to archeological study and the retrieval of artifacts.
See also: maritime archeology