Click here to skip to content

Hydrographic charts

The Map Library has the largest readily accessible collection of hydrographic or ‘Admiralty’ charts, now published by the United Kingdom Hydrographic Office. They cover the seas of the whole world and give coastline, high and low water marks, and soundings. 

UK Charts

The UK Hydrographic Office was established as part of the Admiralty in 1795 with the first official Admiralty chart being issued in November 1800. Nineteenth-century charts may have insets with coastal elevations and topographic views, useful to identify landfalls and prominent fixing marks. The charts may also include: details of coastal forts and other defences; detailed insets of harbours; hazards such as reefs and wrecks; and navigational aids such as buoys and beacons. 

Admiralty charts were constantly updated as out-of-date charts can pose a potential navigational hazard. In the past, redrawn charts could lead to a number in the sequence falling empty, which could then be reused for the chart of a completely different title and area.

From the 1850s, Sailing Directions, called "pilots", have also been published by the Admiralty, Hydrographic Department. They contain maps and notes for seafarers. These are held in the general collection not in the Map Library. Some are also held in the SPIS collections.

The national set of Admiralty charts is maintained by the Hydrographic Office of the Ministry of Defence at Taunton. The collection includes printed and manuscript charts, surveyors’ reports and correspondence of the Hydrographer of the Navy.

Boston Bay and approaches, from the latest United States Government Charts.

Boston Bay and approaches, from the latest United States Government Charts. Admiralty 1899. Maps SEC 7 (1227). Copyright © The British Library Board

Hydrographic charts are also produced by organisations in other countries and a selection of these is held by the Map Library. Notable amongst these are DMAHTC and NOAA charts produced in the United States. Some Russian charts are also held as are miscellaneous charts produced by various governmental bodies form around the world.


Modern Admiralty charts are held at the pressmark Maps B.A.C. and can be ordered via Explore the British Library. The catalogue entry for these charts is entitled ‘Hydrographic Office Charts’ The required area and sheet numbers can be found by consulting the printed Catalogue of Admiralty Charts and Publications [NP 131] in the Maps Reading Room. This information can be entered during the ordering process.

Sheet numbers and titles of older sheets (i.e. 19th century) can be found by consulting the Catalogue of Admiralty Charts and other Hydrographic Publications also to be found in the Maps Reading Room [Maps Ref. Z.5b.12].

Microfiche  of some of these older charts are held in the fiche drawers in the Maps Reading Room.

East India Company charts

The East India Company carried out the charting and marine surveys of the Indian Ocean, China Sea and Eastern Archipelago, from the appointment of the first hydrographer in 1779 until the Company’s demise in 1858. Charts and records of these marine surveys are to be found partly in the India Office Records at the British Library, and partly in the archives of the United Kingdom Hydrographic Office.

Further reading

  • Blewitt, Mary. Surveys of the Seas: A Brief History of British Hydrography. Macgibbon & Kee, 1957.
  • Campbell, Tony. "Episodes from the early history of British Admiralty Charting." The Map Collector, 25 (1983) pp.28-33
  • Day, Sir Archibald. The Admiralty Hydrographic Service 1795-1919. HMSO, 1967
  • Edgell, Sir John. Sea Surveys: Britain’s Contribution to Hydrography. HMSO, 1965.
  • Edwards, H.S. Alexander Dalrymple, F.R.S. (1737-1808). First Hydrographer to the Admiralty. The Map Collector, 4 (1978) pp.19-29
  • Ritchie, G.S. The Admiralty Chart: British Naval Hydrography in the Nineteenth Century. Pentland Press, 1995
  • Whitfield, Peter. The Charting of the Oceans: ten centuries of maritime maps. British Library, London, 1996.