How to look for records of... Sea charts
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1. Why use this guide?
This guide introduces sea charts and explains how to find them at The National Archives, as well as detailing other useful sources and institutions.
2. What are sea charts?
Sea charts are maps for navigation at sea, describing seas, rivers and coasts in many parts of the world. Some show man-made features such as harbours and shore defences. They often include the best and most easily accessible maps of small oceanic islands.
Most show high and low water marks and the depth of water (also known as soundings). Many record navigational hazards such as reefs and wrecks, and navigational aids including lights, buoys and beacons. Though few contain information on areas inland of the foreshore, features which were useful in entering harbour or making landfall are sometimes included, as well as and coastal elevations and topographic views. In addition Admiralty charts from the 19th century may depict sites of archaeological interest, coastal forts and defences, and natural features.
Many sea charts have a compass indicator, and earlier ones often have an elaborate compass rose. Most also have some indication of scale such as a scale bar or representative fraction, or a border showing degrees of latitude and longitude.
3. Sea charts in our collection
We hold many different types of sea charts in both manuscript and printed form. Most were used by the government and armed services, and many bear manuscript annotations and amendments relating to their use.
Maps and charts are original documents which can be viewed in our reading rooms. They are not available to download or view online.
Admiralty charts (1800-)
The Hydrographic Department was established in 1795 as a sub-department of the Admiralty, and issued its first official chart in November 1800.
Manuscript charts and early printed charts
Charts printed before 1800, including those which were published commercially, as well as charts drawn by officers and seamen throughout history.
Records from the United Kingdom Hydrographic Office
Related records are being transferred from the United Kingdom Hydrographic Office, and some are available to order and view in our reading rooms.
4. Where to start
Discovery, our catalogue
Search for sea charts by keyword in our catalogue. Sea charts are distributed throughout our collection, though records of the following departments can be particularly useful:
- United Kingdom Hydrographic Office
- Colonial Office
- Foreign Office
- War Office
- Cabinet Office
Speculative keyword searches may also reveal sea charts as well as documents relating to their creation and use. See below for a list of useful document series.
Finding aids in our reading rooms
Consult the following finding aids in the Map and Large Document Reading Room:
- The four-volume published catalogue of maps and plans in the Public Record Office, arranged topographically
- A partial card index to British Admiralty Charts, arranged by chart order
- The summary calendar of uncatalogued maps (look under the heading ‘Charts: Admiralty’ in the accompanying subject index)
Sea charts elsewhere in our records
Many charts have not yet been individually catalogued and remain to be discovered within ships’ logs, Admiralty station records and other documents. For this reason none of these catalogues or finding aids is fully comprehensive.
Please let us know if you find an unrecorded chart, either by speaking to a member of staff or by filling in the online form titled ‘found and error’ next to the catalogue description.
5. How to find Admiralty charts (1800-)
Admiralty charts may include editions, states and printed amendments not represented elsewhere, although most are of standard issue. Place names and names of coastal features were often recorded, some of which are no longer in use. Some contain details of coastal harbours and surveys of navigable rivers, and their depictions of small oceanic islands can be particularly valuable.
Many charts bear manuscript additions and amendments relating to their use. Individual charts may also accompany correspondence indicating errors or suggesting amendments. As well as complete charts our collection includes portions which were cut away and used to illustrate a particular point. Military and civilian personnel sometimes traced or copied charts in the course of their duties and examples of these also survive.
Admiralty charts were continually updated to ensure they remained accurate and useful, and obsolete charts were destroyed because they presented a navigational hazard. Dates of survey and compilation were carefully recorded as well as those of any corrections. Corrections were often made by modifying the copperplates from which the chart was printed and re-publishing it as a new edition; in other cases the chart was completely re-drawn.
Published Admiralty charts often drew on older surveys, particularly in the early years of the Hydrographic Office, which in extreme cases meant that some charts were based on surveys made more than a century earlier.
Searching by place name or geographical area
Admiralty charts can be found by searching our catalogue in various ways:
- By place names, using broad search terms like “English Channel” rather than names of towns or other features
- Using keywords, like “Australia AND chart AND Admiralty”
- By date, for greater precision, using the advanced search function
These methods will also find any tracings, partial charts and records relating to charts which have been catalogued in detail.
The four-volume published catalogue “Maps and Plans in the Public Record Office, Summary Catalogue and Supplementary Map Catalogue (card index)” contains descriptions of charts alongside those of other kinds of maps and is arranged topographically, making searches by geographical area relatively straightforward.
Searching by Admiralty chart number
Search the numerical card index to Admiralty charts in the Map and Large Document Reading Room. This includes many charts which are not yet described in our online catalogue. Each card provides:
- A brief indication of the geographical area covered by the chart
- The chart’s document reference
But be aware that it does not provide:
- Dates of survey
- Dates of publication or revision
- Details of partial charts, tracings or copies
The card index is cross-referenced to paragraphs of the published catalogues “Maps and Plans in the Public Record Office, volume 2: America and West Indies [AM]” and “Volume 3: Africa [AF or AFR]” which provide fuller descriptions of the charts. An index to charts included in the published catalogue “Maps and Plans in the Public Record Office, volume 4: Europe and Turkey” is included within the volume.
Admiralty charts were initially identified by a title which described the area covered. Since 1839 each chart has also been assigned a number, printed in the bottom right hand corner of each sheet, and this number is now considered to be the primary reference indicator for the chart. Some chart numbers include letter prefixes and suffixes.
Because the Admiralty often re-used chart numbers, remember to check that the area indicated on the card index corresponds to that which you are looking for. For example chart 483 has at different times related to a chart of St. Jago in the Cape Verde islands and to Thursday Island in the Torres Straits off the north coast of Australia, and chart number 695 has been used for both the Cook Straits and for Madagascar.
The subject index volumes of the Summary Calendar of Maps and Plans contain lists of charts under the heading ‘Charts: Admiralty’. These include some charts not yet listed in our catalogue, published catalogues or the card index.
The following records series contain significant numbers of Admiralty charts; click on the links to search them in our catalogue.
|ADM 1||Admiralty and Secretariat Papers 1660-1976|
|ADM 7||Admiralty and Secretariat Miscellanea 1563-1953. The case files relating to the search for Sir John Franklin include numerous successive editions of early charts of Arctic America|
|ADM 116||Admiralty and Secretariat Cases: 1852-1960|
|ADM 137||War of 1914-1918: Admiralty Historical Section: Packs and Miscellaneous Records 1860-1925|
|ADM 199||Admiralty: War History Cases and Papers: 1939-1956|
|ADM 231||Admiralty: Naval Intelligence Reports 1883-1965. Charts illustrating reports on foreign naval strength, coastal defences and so on|
|ADM 352||Admiralty: Hydrographic Department: Original Surveys 1713-1831. This series is accruing|
|CAB 11||Committee of Imperial Defence: Colonial/Overseas Defence Committee: Defence Schemes 1863-1939. Charts illustrating memoranda and instructions to Colonial Governors and officers commanding, concerning schemes for local defence, port regulations and so on|
|CO 700||Colonial Office: Maps and Plans: Series I 1595-1927|
|CO 1047||Colonial Office: Maps and Plans: Series II 1779-1947|
|CO 1054||Colonial Office: Maps and Plans: Post -1940 Collection 1897-1984. Includes items which accrued in the Foreign Office after 1940|
|FO 925||Foreign Office: Maps and Plans: 1700-1940|
|WO 32||War Office: Registered Files: General Series: 1845-1985|
|WO 78||War Office: Maps and Plans: 1627-1953. Include numerous Admiralty charts annotated to show the location and effectiveness of coastal defences|
|WO 192||Fort Record Books: 1892-1957. Many of the books that relate to coastal forts contain Admiralty Charts|
In addition many Admiralty station records, ships’ logs, Colonial Office and Foreign Office original correspondence series, and Embassy and Consular archives are known to contain Admiralty charts.
The surviving original artwork for the views and sketches of coasts and rivers that appear on many Admiralty charts is held as a discrete collection in ADM 344.
6. How to find manuscript charts and early printed charts
The early hydrographic charts in our collection include:
- Medieval portolans (navigational charts based on compass points)
- Manuscript pilot books
- Printed charts from the 17th and 18th centuries, both as individual sheets and in atlas form
Only one portolan has so far been identified in our collection; it shows the eastern Mediterranean and part of the Black Sea, and its document reference is MPB 1/38.
By the 17th century printed charts and pilot books were being commercially published. Our collection includes many printed charts from the 17th and 18th centuries, both as individual sheets and in atlas form. The atlases are catalogued by country, continent and word heading and are therefore best searched using those terms. Bear in mind that the sheets within an atlas may not be individually catalogued.
Early printed charts are known to exist within the following record series (click the links to search our catalogue):
|SP 112||The State Paper Office map collection: c1590 – c1888|
|WO 78||The War Office map library: 1627 – 1953|
|ADM 7||Admiralty miscellanea: 1563 – 1956|
|Library classes of atlases: 1684 – 1906|
Naval officers and seamen continued to draw charts by hand into modern times. The Hydrographic Department original surveys in series ADM 352 contain many manuscript charts dating from the 18th and 19th centuries, which were often used as the basis for published Admiralty charts. Charts were also drawn by hand into ships’ logs and journals; for example the records of voyages of exploration (including those of Captains Cook and Bligh) in series ADM 55 include many charts.
7. Records from the United Kingdom Hydrographic Office
The following Hydrographic Office records have been transferred into our collection:
- Original surveys, which formed the basis for published British Admiralty Charts, in series ADM 352. They date from the 17th to early 19th centuries and include foreign charts gathered by surveyors in the Royal Navy
- Original artwork of the coastal and riverine views that appear on many Admiralty charts, in ADM 344
- Ships’ remark books, which record voyages, often with an emphasis on navigation, in record series ADM 346
Other records are due to be transferred, including:
- Minute books
- Other original artwork
Former Hydrographic Office references can be searched using the ‘search for or within references’ field within the advanced search function of our catalogue.
8. Sea charts and copperplates in other archives
The national record set of Admiralty charts is maintained by the Hydrographic Office, which remains an authorised place of deposit for its own records. It holds an almost complete set of printed Admiralty charts, as well as many related records, including original surveys.
The largest readily accessible collections of Admiralty charts are held by the map department of the British Library and the other legal deposit libraries. If you require a large number of charts, or specific editions, it is best to use these collections:
The National Maritime Museum has a large collection of Admiralty charts and some original surveys. The Royal Geographical Society also holds a significant (but incomplete) collection of Admiralty charts.
Admiralty copperplates were formerly held by the Hydrographic Office and six can still be seen there. The others have been deposited in appropriate national institutions, including the National Maritime Museum and the British Library. Most of the plates (including the surviving plates by Dalrymple and Horsburgh) were presented to the Admiralty Library, which also keeps a list of all the plates and details of where they can be found.
9. Further reading
The following publications are available in The National Archives’ Library:
Vice-Admiral Sir Archibald Day, The Admiralty hydrographic service 1795-1919 (HMSO, 1967)
Rear-Admiral G S Ritchie, The Admiralty chart: British naval hydrography in the nineteenth century (1967, new edition 1995)
Admiralty manual of hydrographic surveying (HMSO, 1938)
M Chriss and G R Hayes, An introduction to charts and their use (third edition, 1964)
Derek Howse and Michael Sanderson, The sea chart: An historical survey based on the collections of the National Maritime Museum (1973)
A H W Robinson, Marine cartography in Britain: A history of the sea chart to 1855 (1962)
Peter Whitfield, The charting of the oceans: Ten centuries of maritime maps (1996)