In the early 1950s, the Royal Navy had a requirement for large numbers of minesweepers to counter the threat to British shipping from Soviet mines in the event of a conventional Third World War. The navy's existing minesweepers were obsolete, while the increasing sophistication of modern mines meant the mine warfare forces could not be supplemented by requisitioned fishing vessels as had been done in previous wars. Large orders were placed for coastal minesweepers (the Ton) and for smaller inshore minesweepers and minehunters intended to operate in inshore waters such as river estuaries (the Ham and Ley classes). As the navy did not have sufficient manpower to operate all the required ships in peacetime, it was planned to lay a large number up in reserve, so they could be manned by reservists (in many cases the crews of the fishing boats which would previously have been used in the same role) in time of emergency.^[1][2][3]

Dittisham was one of the first series of Ham-class ships, with a composite (wooden planking on aluminium framing) hull,^[4] and was 106 feet 9 inches (32.54 m) long overall and 100 feet 0 inches (30.48 m) between perpendiculars, with a beam of 21 feet 2 inches (6.45 m) and a draught of 5 feet 6 inches (1.68 m). Displacement was 120 long tons (120 t) standard and 159 long tons (162 t) full load.^[5] Two Paxman 12-cylinder diesel engines gave a total of 1,100 brake horsepower (820 kW) and drove two shafts, giving a top speed of 14 knots (16 mph; 26 km/h), which corresponded to a speed when sweeping of 9 knots (10 mph; 17 km/h).^[4][5] The design armament for the class was a single Bofors 40 mm L/60 gun, although this was generally replaced by an Oerlikon 20 mm cannon.^[4]

Dittisham was built by Fairlie Yacht and was launched on 23 October 1953 and completed on 29 June 1954.^[6][7] She was placed in reserve in 1955, being laid up at Hythe, Hampshire and Gosport.^[8] In 1968 she became a training tender to HMS Ganges, the Royal Navy's boys' training establishment at RNTE Shotley, where she was used to teach seamanship to the school's students.^[9] In 1973 she transferred to HMS Raleigh at Torpoint in 1973.^[8] In March 1983, she was sold to the Kingston Sea Cadets and became TS Steadfast. In April 1997, she was towed to Pounds Shipyard at Portsmouth and broken up.

• Blackman, R.V.B. ed. Jane's Fighting Ships (1953)
• Blackman, Raymond V. B. (1962). Jane's Fighting Ships 1962–63. London: Sampson Low, Marston & Co., Ltd.
• Brown, David K.; Moore, George (2012). Rebuilding the Royal Navy: Warship Design Since 1945. Barnsley, UK: Seaforth Publishing. ISBN 978-1-84832-150-2.
• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
• Friedman, Norman (1987). "Postwar British Mine Countermeasures - and National Strategy". In Lambert, Andrew (ed.). Warship. Vol. 41. pp. 43–51.
• Gardiner, Robert; Chumbley, Stephen (1995). Conway's All the World's Fighting Ships 1947–1995. Annapolis, Maryland, USA: Naval Institute Press. ISBN 1-55750-132-7.
• Worth, Jack (1986). British Warships Since 1945: Part 4: Minesweepers. Liskeard, UK: Maritime Books. ISBN 0-907771-12-2.