List of British prison hulks
Prison hulks were decommissioned ships that authorities used as floating prisons in the 18th and 19th centuries. They were especially popular in England. The term "prison hulk" is not synonymous with the related term convict ship. A hulk is a ship that is afloat, but incapable of going to sea, whereas convict ships are seaworthy vessels whose purpose was to transport convicted felons from their place of conviction to their place of banishment. Initial authorization and later expansion of use. Parliament initially intended to use the hulks as a temporary measure and so the first  authorization, in 1776, for their use was only for two years. Although some Members of Parliament deplored the hulks the 1776 Act lasted for 80 years. Parliament regularly renewed the Act and even extended its scope "for the more severe and effectual punishment of atrocious and daring offenders". The American Revolutionary War, the French Revolutionary Wars, and the Napoleonic Wars resulted in the availability of superannuated vessels suitable for conversion to prison hulks. Ships-of-the-line were particularly suitable because of their size; in active service they had accommodation for hundreds of crewmen. Hulks ceased to be used in  Great Britain on the final expiry of the Act in 1857. Conversion of decommissioned ships. Converting the ships to prison hulks involved removal of the rigging, masts, rudders, and various other features required for sailing. Some hulks retained some of these features, but all were rendered inoperable or unseaworthy in some way. The internal structure was also reconfigured with various features, including cells, in order to accommodate convicted criminals or occasionally prisoners of war. The hulks, which retained only their ability to float, were typically located in harbours. This made them convenient temporary holding quarters for convicts awaiting transportation to  Australia and other penal colonies within the British Empire. In 1798 the hulks held more than 1,400 out of about 1,900 people waiting for transportation to Australia. Most British prison hulks were decommissioned in the 19th century, although suspected and convicted criminals are still confined aboard ships on occasion for various reasons.