Admiralty charts are nautical charts issued by the United Kingdom Hydrographic Office[1] (UKHO) and subject to Crown Copyright. Over 3,500 Standard Nautical Charts (SNCs) and 14,000 Electronic Navigational Charts (ENCs) are available with the Admiralty portfolio offering the widest official coverage of international shipping routes and ports, in varying detail.
Admiralty charts have been produced by UKHO for over 200 years, with the primary aim of saving and protecting lives at sea. The core market for these charts includes over 40,000 defence and merchant ships globally. Today, their products are used by over 90% of ships trading internationally.
History
The British admiralty charts are compiled, drawn and issued by the Hydrographic Office. This department of the Admiralty was established under Earl Spencer by an order in council in 1795, consisting of the Hydrographer, Alexander Dalrymple, one assistant and a draughtsman. The initial remit was to organise the charts and information in the office, and to make it available to His Majesty's ships.[2]:101
Chart design and production
The Hydrographic Department began printing charts in 1800, with the acquisition of its first printing press.[3] Initially charts were produced only for use by the Navy, but in 1821, Thomas Hurd, who had succeeded Dalrymple as Hydrographer in 1808, persuaded the Admiralty to allow sales to the public.[4]:27[5]:105–106 The first catalogue of Admiralty charts was published in 1825, and listed 756 charts.[6]
Admiralty Chart of the coast of Peru, surveyed by Robert FitzRoy in 1836, engraved in 1840, and published with corrections to 1960
Charts were printed from copper plates. Plates were engraved, in reverse, with a burin. The plate was inked, and the excess ink wiped from the flat surface before printing, so that ink remained only in the engraved lines (intaglio printing). The process allowed very fine detail to be printed, but was slow. When corrections or alterations were needed to a chart, the copper was hammered from behind, the raised section scraped and smoothed, and the new information engraved on the smoothed area.[7]:426 This allowed plates to continue in use for long periods, in some cases for over a hundred years.
Charts often showed a great deal of detail of features on land as well as sea. Depths were shown by individual soundings while hills and mountains were shown by hatch marks. Printing was in black and white, but some charts were hand-coloured, either to emphasise water depth or terrain, or to indicate specific features such as lighthouses.
Part of an 1872 Admiralty chart of Sicily showing Mount Etna and the port of Riposto. The orange indicates the position of a lighthouse.1900 Admiralty Chart of Portree Harbour, using contours for the hills
Experiments were made with the use of lithography from the 1820s, but results were not entirely satisfactory. Lithography was less expensive, and some charts were printed in this way, but printing from copper plates continued to be the main method into the 20th-Century, and in both cases from flat-bed printing machines.[8]:10[9] The most common chart size was early established as the "Double-elephant", about 39 X 25.5 inches, and this has continued to be the case.[10] Chart design gradually simplified over the years, with less detail on land, focusing on features visible to the mariner. Contours were increasingly used for hills instead of hatching.
All printing of Admiralty charts was carried out in England until the first World War. In 1915, the survey ship HMS Endeavour was sent to support the Gallipoli campaign, and carried printing equipment so that charts from her surveys could be rapidly made available to the fleet. In 1938 trials were made with the rotary offset process, using a zinc plate copied from the copper original. These were successful, and by the outbreak of World War II all chart production used this process, which was faster, and reduced wear and tear on the copper original. This development was crucial in meeting the increased wartime demand for charts.[8]:81 During World War II the distribution of printing facilities was on a much larger scale than previously. There was also concern about the safety of the original printing plates in the event of air raids, and high quality baryta paper proofs were made as backups.[8]:119
1965 Admiralty Chart of Ravenna and Porto Corsini showing depth colouring
From the late 1940s, developments in printing technology made colour printing possible with sufficient accuracy for chart work. The first use of printed (as opposed to hand-drawn) colour was in marking of water depths. Solid pale blue was used for water to the 3 fathom line, and a ribbon of blue for six fathoms.[11]
Part of an early "new style" Admiralty chart, of Risavika in Norway, published in 1970. Depth in metres (and tenths of metres for depths less than 20m).
Metrication of Admiralty charts began in 1967, and it was decided to synchronise this with the introduction of a new style of chart, with increased use of colour, which continues in use today. The most striking change is the use of buff for land. Green is used for drying (intertidal) areas, and magenta to indicate lights and beacons. Thus the chart coloration gave a clear indication to users as to whether they were using a chart with depths in fathoms or feet. While depths and heights were in metres, the nautical mile continued to be an international standard. Derived from the length of 1 minute of latitude, it is defined as 1852 metres.[12][13][14][15]
Surveying
Initially, surveys and explorations continued to be commissioned directly by the Admiralty, for example Flinders' circumnavigation of Australia in 1801–3, [5]:75–91 and Beaufort's survey of the southern coast of Turkey (then called Karamania) in 1811–1812.[16] Under Hurd, the Hydrographic Office became more involved in surveying work, and by 1817 there were three vessels specifically assigned to the surveying service, HMS Protector, HMSShamrock, and HMSCongo.[4]:26–29 This continued, particularly under Francis Beaufort, Hydrographer from 1829 to 1855.[5]:189–199
Over the following century the surveying service expanded in both size and reach, becoming a global operation. Several accounts record this history in detail. Llewellyn Styles Dawson was a surveyor particularly noted for his work in China (1865-1870) and a naval assistant in the department for five years (1876-1881).[4]:151–152 During the latter period he commenced work on the two-volume Memoirs of Hydrography which described the Royal Navy's surveying activities between 1750 and 1885, and presented biographies of the officers involved in the activities.[17] The history was continued to 1917 by Archibald Day, Hydrographer from 1950 to 1955 in his The Admiralty Hydrographic Service from 1795-1919, explicitly described as a continuation of Dawson's Memoirs.[4]:5–6Thomas Henry Tizard published a chronological list of the officers and vessels conducting British maritime discoveries and surveys until 1900.[18] These works are all in the public domain. Roger Morris, Hydrographer from 1985 to 1990, published Charts and Surveys in Peace and War 1919-1970, a further continuation of Memoirs.[8] A less formal account of British Naval Hydrography in the 19th-Century is given by Steve Ritchie, Hydrographer 1966–1971, in The Admiralty Chart.[5] Tony Rice has produced a listing and description of the vessels involved in surveying and oceanographic work from 1800 to 1950.[19]
View of Heraklion harbour by Thomas Graves, from Admiralty Chart No 1904 (1897)
A number of major overseas surveys were completed in the years to 1855, a period dominated by Francis Beaufort, Hydrographer from 1829 to 1855. Owen carried out his survey of East Africa from the Cape of Good Hope to Cape Guardafui on the Horn of Africa in 1822–1825, an operation that cost the lives of more than half of the crew due to tropical illness.[5]:107–135 The second voyage of the Beagle to South America (1831-6) is mostly famous for the scientific importance of Darwin's observations and collections, but Captain Robert Fitzroy's surveys of the coast of South America from the River Plate to Ecuador via the Straits of Magellan have been described as a "monumental achievement",[16]:255 and as "opening up the South American continent to European trade".[5]:220Thomas Graves was working in the Mediterranean from 1836 to 1850. Like a number of surveyors before and since, he explored the antiquities and natural history of the numerous places he charted.[5]:269 In 1841-7 Edward Belcher was engaged in the Far East, including making the first survey of Hong Kong.[5]:221–237 The longest running survey was that of Bayfield, whose survey of the Canadian coasts, the St. Lawrence River and the Great Lakes occupied him from 1816 to 1856.[20]
Surveys in home waters were also important. What Robinson (1962) described as the "Grand Survey of the British Isles" began with the appointment of George Thomas as Head Maritime surveyor. Thomas and a series of able surveyors including Michael Slater, Henry Otter, Charles Robinson, William Hewett and Frederick Beechey surveyed the coasts of Britain and Ireland over the next 30 years. Thomas developed techniques for extending triangulation over the shallow waters of the Thames Estuary and the southern part of the North Sea, allowing the exact positions of treacherous sand banks to be determined for the first time.[2]:127–142 These surveys added large numbers of new charts, as well as improvements to old ones. By 1855, when Beaufort retired, the survey of the coasts of the United Kingdom was complete,[5]:248 and there were about 2,000 charts in the catalogue, covering all the oceans of the world.[7]:426
An important survey in 1870 was the Suez Canal. Britain had remained aloof in the early stages of the project, believing it to be impracticable. When the canal was nearing completion, the question arose as to its suitability for naval ships. George Nares in HMSNewport traversed the canal in both directions taking soundings and making measurements, and also surveyed the approaches. This led to the canal becoming an established route for the Royal Navy. [5]:317–319[4]:82
Part of Admiralty Chart of the southern Red Sea, showing Avocet Rock, to the north of Jebel Zukur
As well as the "grand surveys" much detailed work was needed. A particular concern was finding isolated rocks. These were easily missed by soundings with lead and line, which did not give any information about the depths between the soundings.[21] In 1887, two ships were lost in the southern Red Sea, fortunately without loss of life, after striking an uncharted reef close to a major shipping lane. Several attempts to find this were made before HMS Stork found it (and nearly struck it) in 1888. It was named Avocet Rock after the first ship to strike it.[22][4]:143[23]
Ship's boat fitted with "portable" echo-sounding gear, 1930s
Technical developments over the years improved surveying methods and the accuracy of the charts. For depth determination, methods of measuring depth from a moving ship were developed, as well as "sweeping", dragging a horizontal line across an area to detect hazards that might be missed by individual soundings.[24] Echo sounding was introduced in the 1920s, and Percy Douglas, hydrographer from 1924 to 1932, was a strong advocate of this method. As well as increasing productivity, it enabled continuous monitoring along a sounding line, reducing the chance of a hazard being missed.[25][26] Isolated rocks between sounding lines could still be missed, and it was not until the development of sideways-looking sonar in the 1960s and 70s that this risk could be eliminated.[23]
Features of modern charts
Most navigation today uses GPS chart plotters with electronic charts. Paper charts continue to be issued, and are valuable for passage planning and course plotting.
The scale of the charts can vary according to purpose; large-scale charts often cover approaches to harbours, such as Port Approach Guides, medium-scale charts often cover frequently used coastal areas, and small-scale charts are regularly used for navigation in more open areas. A series of small craft charts are also available at suitable scales.[27][28]
Admiralty charts include information on: depths (chart datum), coastline, buoyage, land and underwater contour lines, seabed composition, hazards, tidal information (indicated by "tidal diamonds"), prominent land features, traffic separation schemes radio direction finding (RDF) information, lights, and other information to assist in navigation.[28]
Admiralty Gnomonic Chart of the North Atlantic, used to find the shortest track (portion of a great circle) between two points. A straight line is drawn between the two points on this chart, and the resulting great circle track is transferred to a Mercator chart, plotting the latitudes of the points of intersection of the track with the several meridians
Navigation charts at a scale of 1:50,000 or smaller (1:100,000 is a smaller scale than 1:50,000) use the Mercator projection, and have since at least the 1930s.[29][30] The Mercator projection has the property of maintaining angles correctly, so that a line on the earth's surface that crosses all the meridians at the same angle (a rhumb line) will be represented on the chart by a straight line at the same angle. Thus if a straight line is drawn on the chart from A to B, and the angle determined, the ship may sail at a constant bearing at that angle to reach B from A. Allowances for magnetic variation and magnetic deviation must also be made. However, a rhumb line is not in general the shortest distance between two points, which is a great circle. (The equator and lines of longitude are both great circles and rhumb lines.) When navigating over longer distances the difference becomes important, and charts using the gnomonic projection, on which all great circles are shown as straight lines, are used for course planning.[30] In the past, the gnomonic projection was widely used for navigation charts, and also for polar charts.[29]
Since the late 1970s, all charts at a scale of 1:50,000 or larger have used the transverse Mercator projection,[30] which is the projection used for the Ordnance Survey National Grid. Topography on Admiralty charts of the UK is generally based on Ordnance Survey mapping. For the small areas depicted on such maps, the differences between projections are of no practical importance.[30]
Admiralty charts are issued by the UKHO for a variety of users; Standard Nautical Charts (SNCs) are issued to mariners subject to the Safety of Life at Sea (SOLAS) convention, while chart folios, at a convenient A2 size, are produced for leisure users.[28] Alongside its paper charts, UKHO produces an expanding range of digital products to fulfil the impending compulsory carriage requirements of ECDIS/ENCs, as issued by the International Maritime Organization (IMO).
The digital range comprises Electronic Navigational Charts (ENCs) for use with an Electronic Chart Display and Information System (ECDIS), which can be displayed and interrogated through Admiralty Vector Chart Service (AVCS).[27] The range also includes Admiralty Raster Chart Service (ARCS), which allows paper nautical charts to be viewed in raster form on an ECDIS.[28]
Due to the changing nature of the seabed and other charted features, chart information must be up-to-date to maintain accuracy and general safety. This is ensured by UKHO continually assessing hydrographic data for vital safety information, with urgent updates issued via weekly Notices to Mariners (NMs)
A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 m), used especially for measuring the depth of water. The fathom is neither an international standard (SI) unit, nor an internationally accepted non-SI unit. Historically it was the maritime measure of depth in the English-speaking world but, apart from within the US, charts now use metres.
Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection.
A nautical chart or hydrographic chart is a graphic representation of a sea region or water body and adjacent coasts or banks. Depending on the scale of the chart, it may show depths of water (bathymetry) and heights of land (topography), natural features of the seabed, details of the coastline, navigational hazards, locations of natural and human-made aids to navigation, information on tides and currents, local details of the Earth's magnetic field, and human-made structures such as harbours, buildings, and bridges. Nautical charts are essential tools for marine navigation; many countries require vessels, especially commercial ships, to carry them. Nautical charting may take the form of charts printed on paper or computerized electronic navigational charts. Recent technologies have made available paper charts which are printed "on demand" with cartographic data that has been downloaded to the commercial printing company as recently as the night before printing. With each daily download, critical data such as Local Notices to Mariners are added to the on-demand chart files so that these charts are up to date at the time of printing.
Sir Francis Beaufort was an Irish hydrographer, the creator of the Beaufort cipher and the Beaufort scale, and a naval officer.
A hydrographic office is an organization which is devoted to acquiring and publishing hydrographic information.
The United Kingdom Hydrographic Office (UKHO) is the UK's agency for providing hydrographic and marine geospatial data to mariners and maritime organisations across the world. The UKHO is a trading fund of the Ministry of Defence (MoD) and is located in Taunton, Somerset, with a workforce of approximately 900 staff.
Thomas Henry Tizard was an English oceanographer, hydrographic surveyor, and navigator.
The Hydrographer of the Navy is the principal hydrographical Royal Naval appointment. From 1795 until 2001, the post was responsible for the production of charts for the Royal Navy, and around this post grew the United Kingdom Hydrographic Office (UKHO).
The Nautical Magazine was a monthly magazine containing articles of general interest to seafarers. The magazine was first published in 1832 by Simpkin, Marshall, and Co. (London) as The Nautical Magazine: A Journal of Papers on Subjects Connected with Maritime Affairs in General and then as The Nautical Magazine And Naval Chronicle. From 1891 the title was modified to Nautical Magazine and Journal of the Royal Naval Reserve and it was published by Brown, Son and Ferguson, (Glasgow), who continued to produce it until it was acquired and merged into Sea Breezes in 2011.
Rear-Admiral George Stephen Ritchie CB DSC was a British admiral noted for his cartographic and hydrographic work and as an author of many publications on hydrography. He was Hydrographer of the Navy from 1966 to 1971.
John Washington was an officer of the Royal Navy, Hydrographer of the Navy, and a founding member of the Royal Geographical Society of London.
The National Hydrographic Office, formerly the Indian Naval Hydrographic Department (INHD), headed by the Chief Hydrographer to the Government of India, is an Indian government agency responsible for hydrographic surveys and nautical charting in India. Its headquarters National Hydrographic Office is located in Dehradun, Uttarakhand beside the Principal Controller of Defense Accounts Office. Presently, the department is equipped with Seven indigenously built survey ships including a catamaran hull survey vessel (CHSV). The National Institute of Hydrography is the training institute to impart knowledge regarding hydrography and to train its personnel. Two more ships are currently being constructed and is expected to be commissioned into service by 2025-26.
The Russian Hydrographic Service, full current official name Department of Navigation and Oceanography of the Ministry of Defence of the Russian Federation, is Russia's hydrographic office, with responsibility to facilitate navigation, performing hydrographic surveys and publishing nautical charts.
Admiral Sir Arthur Mostyn Field, was a senior officer in the Royal Navy who served as Hydrographer of the Navy from 1904 to 1909.
Peter Frederick Shortland was a British naval officer and hydrographic surveyor. He was noted for his work in North America, and for surveys involving deep soundings, particularly in preparation for the laying of submarine cables.
Vice-Admiral Sir John Augustine Edgell, KBE, CB, FRS was an officer in the Royal Navy and Hydrographer of the Navy from 1932 to 1945. He was noted for his support for innovations such as echo sounding and radio navigation, for the surveying and chart production operations of his department during World War II, and for his advocacy of the science of oceanography
William Hewett was a Royal Navy officer noted for making the first comprehensive survey of the North Sea and for his work on tides.
George Thomas was a Master in the Royal Navy who was one of the early surveyors of the coasts of Great Britain
Vice-Admiral Sir Archibald Day, was an officer in the Royal Navy and Hydrographer of the Navy from 1950-1955. He played an important part in planning the evacuation from Dunkirk in 1940, and wrote a history of the Hydrographic Service.
Admiral Sir Frederick Charles Learmonth was a Royal Navy officer.
1 2 Robinson, Adrian Henry Wardle (1962). Marine Cartography in Britain: A History of the Sea Chart to 1855. With a Foreword by Sir John Edgell. Leicester University Press. OCLC62431872.
↑ David, Andrew (2008). Liebenberg, Elri; Demhardt, Imre Josef; Collier, Peter (eds.). The emergence of the Admiralty Chart in the nineteenth century. International Cartographic Association. pp.1–16. ISBN9780620437509.
1 2 3 4 5 6 7 8 9 10 Ritchie, George Stephen (1967). The Admiralty Chart: British Naval Hydrography in the Nineteenth Century. Hollis & Carter. OCLC1082888087.
1 2 3 4 Morris, Roger O. (1995). Charts and Surveys in Peace and War: The History of the Royal Navy's Hydrographic Service, 1919-1970. H.M. Stationery Office. ISBN978-0-11-772456-3.
1 2 Friendly, Alfred (1977). Beaufort of the Admiralty: The Life of Sir Francis Beaufort, 1774-1857. Hutchinson. pp.182–217. ISBN978-0-09-128500-5.
↑ Dawson, Llewellyn Styles (1885). Memoirs of hydrography, including brief biographies of the principal officers who have served in H.M. Naval Surveying Service between the years 1750 and 1885. Eastbourne: Henry W. Keay. Part 1. - 1750 to 1830; Part 2. - 1830-1885.
↑ Dobson, Richard (2002). "International Co-operation to Improve Safety of Navigation in the Southern Red Sea". The International Hydrographic Review. 3 (2): 35–44.
1 2 3 4 Tom Cunliffe. The Complete Day Skipper: Skippering with Confidence Right From the Start. Adlard Coles; 5 edition (2016), 208 pag. ISBN1472924169, ISBN978-1472924162
1 2 3 4 Great Britain.Ministry of Defence (Navy) (1987). Admiralty manual of navigation. Vol. 1, General navigation, coastal navigation and pilotage, Revised 1987. London: The Stationery Office. pp.108–109.
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