The Ritchie Collection comprises books, pamphlets, atlases and charts relating to the history of Hydrography, the branch of marine science concerned with studying, surveying and mapping the earth's seas and waters. The collection represents the personal library of the former Hydrographer to the Royal Navy, Rear Admiral George Stephen Ritchie (b. 1914). Its contents reflect Rear Admiral Ritchie's professional achievements, as well as his personal interest in the history of Hydrography and surveying. Technical and cartographic material sits alongside numerous primary and secondary texts on the history of Hydrography, as well as publications on the broader themes of seafaring and exploration.

There are contemporary accounts, including The Surveying Voyage of HMS Flag by Captain R. N. Blackwood (1848) and An Account of the Natives of the Tonga Islands by William Mariner (1817), as well as more recent histories such as Vice Admiral Sir Archibald Day's The Admiralty Hydrographic Service 1795-1919 (1967). The great pioneers in the field, including James Cook and William Fitzwilliam Owen, are also represented. Many of the secondary texts in the collection are authors' signed copies and Rear Admiral Ritchie's own works are present, too, including Challenger: the Life of a Survey Ship (1957), a biography of the ship commanded by him on a celebrated voyage of 1951-1952.