Abstract: The present invention relates to drinking vessels and more particularly to drinking vessels having an arcuate bottom which will not allow the drinking vessel to be positioned atop a substantially planer surface unless a specially adapted coaster is utilized. The drinking vessel includes a body having an upper portion including an opening for receiving and dispensing liquids and a bottom having a substantially arcuate outer surface. The coaster includes a recessed area for fittingly receiving the arcuate bottom of the drinking vessel and optionally a groove for receiving a portion of a handle which projects from the drinking vessel.