I also have a memory - although I still can't picture Granddad in it- of him taking me on a trip aboard the Medway Queen. The Medway Queen was a paddle steamer that ran from Sun Pier, Chatham, to Southend.
Built in about 1924, she served as a minesweeper during World War II but her real moment of glory was in 1940 when she made seven trips to the Dunkirk beaches, rescuing about 7,000 men and shooting down three German aircraft. returned to civilian use after the war, she was taken out of service in 1963 before being used as a night club on the Isle of Wight. She was eventually restored (rebuilt?) and is now back on the River Medway, moored at Gillingham Pier.
All this was brought to mind as I see there is a programme about the Dunkirk evacuation on television tonight.