The Cornish Lugger When I first sailed with Mike and Sue on board the Deu Kerens some fifteen years ago I did not know what a lugger was. I had visions of a very sturdy boat 'lugging' heavy loads of granite and slate around the coasts. Little did I know.The term 'Lugger' is derived from a Norse word meaning Square. The 'Lug sail' had been used on the Viking longboats and even then it had been proven in use for thousands of years. Square sails were used on the fast tea and wool clipper ships because of their 'windjamming' capability. The lug sail is probably the most powerful sail ever devised. Cornish luggers were built primarily as fishing vessels where it was vital to get the catch back to market as quickly as possible.