Studied at the Universities of St Andrews and Manchester, and is a former curator of paintings, drawings and prints, and co-ordinator of various exhibitions and galleries, at the National Maritime Museum, Greenwich, also lecturer and ships' historian on board cruise ships. Publications include illustrated histories of Marine Painting (1995) and yachting art Yachts on Canvas (1998), The Voyage of the Beagle: Darwin’s extraordinary adventure aboard FitzRoy’s famous survey ship (2008), Careless Talk Costs Lives: Fougasse and the Art of Public Information (2010) and Your Country Needs You: the Secret History of the Propaganda Poster (2013), Dazzle: Disguise and Disruption in War and Art (2016) and Picturing the Pacific: Sir Joseph Banks and the Shipboard Artists of Cook and Flinders (2018). Completed his PhD at the University of Sussex in 2015 on the voyager artist William Westall (1781-1850) who sailed with Commander Matthew Flinders aboard HMS 'Investigator' (1801-1803) the first ship to circumnavigate Australia.

Guided tours of the buildings and artworks of the National Maritime Museum can be arranged for groups.