Where is the Celtic sea and why choose it as a name for a group of kayakers? "The Celtic Sea" otherwise known as “An Mhuir Cheilteach” is the area of the Atlantic Ocean off the south coast of Ireland. It is bounded to the east by Saint George's Channel, the Bristol Channel and the English Channel, as well as adjacent portions of Wales, Cornwall, Devon and Brittany. The Celtic heritage of the bounding lands gives the sea its name, first proposed by E. W. L Holt in 1921. The northern portion of this sea had previously been considered part of Saint George's Channel and the southern part had no common name; the need for a common name came to be felt because of common geology and hydrology. The name is now commonly used by workers in the oil and fishing industries. The southern and western boundaries are less clearly defined.