A plimsoll shoe, plimsole, or plimsoll is a type of athletic shoe with a canvas upper and rubber sole, developed as beachwear in the 1830s by the Liverpool Rubber Company (later to become Dunlop). The shoe was originally, and often still is in parts of the UK, called a 'sand shoe' and acquired the nickname 'plimsoll' in the 1870s. This name derived, according to Nicholette Jones' book "The Plimsoll Sensation", because the coloured horizontal band joining the upper to the sole resembled the Plimsoll line on a ship's hull, or because, just like the Plimsoll line on a ship, if water got above the line of the rubber sole, the wearer would get wet.
source: wikipedia
