Dwan was born in Rotherhithe, London to a family of lightermen in the Port of London. He joined Poplar Blackwall and District Rowing Club at the age of 12 initially as a cox but soon as an oarsman. When he was 15 he was apprenticed as lighterman to his grandfather Williams and this allowed him to enter the novice sculls in the National Dock Labour Board (NDLB) regatta at Putney. He won the race which included contestants of that year’s Doggett's Coat and Badge Race. While he was sculling he continued working as a lighterman and worked for Humphrey & Grey starting as a boy in the tug Sir John. After two year with Humphrey & Grey he obtained his lighterman’s licence and went on the dock labour pool to experience a variety of firms. During 1967 the decasualisation scheme following Devlin’s report was implemented and all dock workers had to be allocated to an employer. Dwan was allocated to F.T. Everard at Greenhithe, of whom he said “The management were very good to me in allowing me time to train. I could not have wished for better employers”.
In 1968 Dwan was runner-up in the Diamond Challenge Sculls at Henley Royal Regatta. He also competed for Great Britain in the single scull in the 1968 Summer Olympics in Mexico. He reached the final and came 6th overall. Also in 1968 he won the Wingfield Sculls for the first time. He won the WIngfield Sculls again in 1969, 1970, 1971 and 1972. In 1972 he competed again for Great Britain in the single scull in the Summer Olympics in Munich when he came 9th. Dwan was runner up in the Diamond Challenge Sculls in 1974 and won the Wingfield Sculls for the sixth time in 1975.
In 1977 Dwan was accepted as one of Royal Watermen during the Queen’s Jubilee Year. Dwan continued to work as a lighterman, but with severance at the docks, he decided to work for himself and withdrew from lighterage and rowing at the same time. For a while he worked on the building of the Thames Barrier, and then on pleasure boats on the River Thames. He then went into business with Bill Ludgrove and set up their own company Thames Cruises. The business grew and they bought a repair yard at Eel Pie Island. Thames Cruises owned the pleasure boat Marchioness which was sunk with loss of life in the Marchioness disaster when the pleasure boat collided with a dredger ""Bowbelle" in August 1989. The disaster was found by the Marine Accident Investigation Branch to have been caused by the poor visibility from each ship's wheelhouse, the fact that both vessels were using the centre of the river, and that no clear instructions were given to the look-out at the bow of the Bowbelle. Twelve years later another report by Lord Clarke also blamed poor lookouts on both vessels for the collision and criticised the owners and managers of both vessels for failing to properly instruct and monitor their crews. In 2004 Dwan was appointed Queen's Bargemaster, being responsible for the safety of the Queen when she travelled by water. However in the light of protests because of his involvement with the Marchioness disaster, he resigned.
- PORT OF LONDON, MARCH/APRIL 2003
- Henley Royal Regatta Results of Final Races 1946–2003 Archived 16 July 2011 at the Wayback Machine
- Sports Reference Olympic Sports – Kenneth Dwan
- Wingfield Sculls Record of Races
- Telegraph – Andrew Sparrow and Peter Foster Lookouts could have prevented the collision 24 Mar 2001
- Evening Standard Patrick Sawer and Clair Weaver Bargemaster quits over disaster links 22 January 2004