Metropolitan Police Marine Policing Unit

The Marine Policing Unit (MPU), formally known as Thames Division, is a Central Operations (CO) branch of London's Metropolitan Police Service. Its forerunner, the Marine Police Force, was England's first recognised preventive police unit.

The MPU is headquartered on Wapping High Street, in the east of the city, from where it operates a fleet of vessels responsible for policing the River Thames within Greater London.

Thames Division was formed in 1839 when the Marine Police Force was absorbed into the Metropolitan Police Force. The original marine force is considered the first preventive police unit in the history of policing in England. It began when a merchant and magistrate, Patrick Colquhoun, teamed up with mariner John Harriott and Jeremy Bentham to persuade shipping companies to finance a police force to prevent the theft of cargo from London's docks. The first death of an officer in the line of duty occurred shortly thereafter, when Gabriel Franks was killed in a skirmish with dock workers protesting against the new force. Impressed by the economic impact of the initiative, the government passed the Marine Police Bill on 28 July 1800, making it one of the first publicly funded police forces, and also the first uniformed police force in the world.

Initially, patrols were conducted in rowing boats, some of which remained in use until 1905. Impetus to change was provided when, on 3 September 1878, the steam collier Bywell Castle ran into the pleasure steamer Princess Alice in Galleons Reach, resulting in the loss of over 600 lives. The subsequent inquest and inquiry recommended that Thames Division should have steam launches, as rowing galleys had shown themselves to be inadequate for police duty, and the first two were commissioned in the mid-1880s. In 1910 the first motor vessels were introduced.

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