This is a very interesting and rare English surname. It is recorded in the International Genealogical Index from Stuart times in the 17th century, but does not seem to appear in any of the various dictionaries of surnames of the past five centuries. On the face of it the meaning is somebody who lived at a low water mark on the sea shore, but this is not logical, as one could hardly live at the low water mark without being drowned! We believe that the surname means almost the opposite, and is probably locational. If so it may well originate from a now 'lost' medieval village, whch if it existed at all, developed from the pre 7th century Olde English and Norse words 'Hlaw-vatr. This means a hill by the water, or possibly a waterfall and is similar in construction to Wassand, a village in East Yorkshire and meaning 'The sand bank by the water' or Wastwater in Cumbria, meaning 'The valley of water.' All this is conjecture, but is based on many years experience of researching obscure surnames. Examples of recordings taken from the surviving church registers of the city of London include William Lowater who married Hester Emme at Allhallows, London Wall, on December 31st 1685, and John Lowater who married Allice Derrick at St Leonards Shoreditch, on October 15th 1793.