Thekla is a former cargo ship moored in the Mud Dock area of Bristol's Floating Harbour, England. The ship was built in Germany in 1958 and worked in the coastal trades. In 1982 the ship was bought by Ki Longfellow-Stanshall, the wife of Vivian Stanshall, refitted, and brought to Bristol in 1983 as the Old Profanity Showboat. It was used as a theatre to showcase music of every sort, including cabaret, comedy, plays, musicals, and poetry events. The ship also contained an art gallery.