The Thames Division was formed in 1839 when the Marine Police Force was amalgamated with the Metropolitan Police Force. In these early days, the police carried out their duties in rowing boats, some of which were still in use in 1905. The Metropolitan Police Service (MPS) (usually just referred to as the Metropolitan Police, its former official name, or the Met) is the territorial police force in Greater London, England, with the exception of the square mile of the City of London, which has its own police force, the City of...

Unfortunately, however, on the 3 September 1878 a terrible marine disaster occurred on the River Thames claiming the highest ever single loss of civilian lives in UK Territorial Waters. The iron ship ' Bywell Castle' ran into the pleasure steamer 'Princess Alice' in Galleons Reach (East London), downstream of Barking Creek with the loss of over 600 lives. Length 346 km Elevation of the source 110 m Average discharge entering Oxford: 17. ...

At the subsequent inquest and inquiry, officials recommended that Thames Division should have steam launches as rowing galleys were inadequate for Police duty and the first two were commissioned in the mid 1880's. By 1898 Thames Division had a further 8 steam launches to supplement its 28 rowing galleys until 1910 when the first motor vessels were introduced.

Just over a hundred years after the Princess Alice tragedy Thames Division found themselves being called upon to deal with another disaster. At about 1.50am on the 20th August 1989 the aggregate dredger 'Bowbelle' collided with the passenger vessel 'Marchioness' near Cannon Street Railway Bridge. Four police patrol boats were on the scene within six minutes and with the assistance of the passenger vessel 'Hurlingham' rescued 87 people from the river that night. In the days that followed river police officers recovered a total of 51 bodies, 24 from the wreck and 27 from the River.

After subsequent inquiries, the Government asked the Maritime and Coastguard Agency ( MCA ), the Port of London Authority ( PLA ) and the Royal National Lifeboat Institution ( RNLI ) to work together to set up a dedicated Search and Rescue service for the tidal River Thames. Consequently, on the 2nd January 2002, the RNLI set up four lifeboat stations at Gravesend, Tower Pier, Chiswick Pier and Teddington . RNLI Lifeboat at Calshot Spit The Royal National Lifeboat Institution (RNLI) is a charity dedicated to saving lives at sea around the coasts of the United Kingdom and the Republic of Ireland. ...

In 2001 the Thames Division was renamed the Marine Support Unit.