A cooper is a person trained to make wooden casks, barrels, vats, buckets, tubs, troughs, and other similar containers from timber staves that were usually heated or steamed to make them pliable.

Jack Tar is a common English term that was originally used to refer to seamen of the Merchant Navy or the Royal Navy, particularly during the British Empire. By World War I the term was used as a nickname for those in the US Navy. Members of the public and seafarers alike made use of the name in identifying those who went to sea. It was not used pejoratively, and sailors were happy to use the term to label themselves.