The large sea level rise was at the end of the last Ice Age when the sea rose at the rate of about a metre a century. I'm not sure how much the sea level rose by, however. The myth of the flood and the destruction of 'Atlantis' as well as the flooding of the eastern land bridge to the European mainland occurred. There has been a sea level rise since the Neolithic - perhaps about a metre or two. ( http://www.stonepages.com/france/erlannichi.html ) The current sea level rise is 1.8mm/year - but the rate appears to be doubling every two or three years. The ice sheets that are now breaking up are reckoned to raise the sea level by about fifty or sixty metres !