Dogget's coat and badge. The first prize in the Thames rowing-match, given on the 1st of August every year. So called from Thomas Dogget, an actor of Drury Lane, who signalised the accession of George I. to the throne by giving a waterman's coat and badge to the winner of the race. The Fishmongers' Company add a guinea to the prize. The race is from the “Swan” at London Bridge to the “Swan” at Chelsea.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894