The Channel Islands are a self-governing territory under the British Crown. The British Ordnance Survey (OS) has made a large contribution to the mapping of the islands, but they are nearer to France than mainland Britain, are not covered by the National Grid and have their own mapping agencies. Several commercial survey companies have also been involved in official mapping, resulting in a varied range of topographic and tourist maps, with specifications differing from island to island.
The smaller scale mapping of Jersey has evolved from a two inches to the mile (1:31,680) map first published by the Ordnance Survey office at Southampton in 1914, and based upon survey by the Royal Engineers the previous year. This map was used as a base for revision by BKS Surveys Ltd (BKS) in 1960, when it acquired the title Official map of Jersey. BKS also produced a larger format map at 1:15,840 scale in the same year. Subsequently, other private mapping companies have provided official and unofficial tourist maps of the island. Hunting Surveys remapped the island to produce a new official map at 1:25,000 and a simpler 1:50,000 road map, with a street map of St. Helier on the reverse. This appears as a military edition in the (M824 Series) dated 1969, and was last revised in its civilian version in 1975. It has 25 ft contours and layer coloured relief, and is on the UTM projection with UTM grid. The compilation was from 1:2,500 scale surveys and 1965 air photography. OS were commissioned by the States of Jersey in 1980 to update the island’s mapping. The basic map is at 1:1,000 scale, with 209 sheets needed to cover the island. There is also a series at 1:2,500 (45 sheets) and 1:5,000 (14 sheets). The latter is contoured at 10 m intervals. All these maps are in monochrome and are available as diazo paper prints or as transparencies. Following a study of digital map requirements, all the 1:2,500 scale mapping was digitized by Ordnance Survey to the Land-Line.93 Plus specification, and in 1994 the States of Jersey purchased a Laser-Scan Horizon map management system for using the digital data in a GIS environment. The current single-sheet map, published in 1982, and reprinted with minor revisions in 1988, was compiled from air photography flown in 1979 and 1980 and has a contour interval of 20 ft.
Guernsey has a similar history of OS mapping. The island was surveyed in 1898-99 at 1:2,500 scale (in 26 sheets) and at six inches to the mile, and this survey formed the basis for many subsequent maps. For example, OS updated the mapping in 1938, and a further update was made in 1962-3 by BKS Surveys, together with enlargement of 1:2,500 sheets to 1:1,250 for St. Peter Port. Contours at 10 ft intervals were added at this time. Further revisions by BKS took place in 1979, while OS updated the St. Peter Port sheets in 1988. There is also a number of 1:500 scale plans produced by specialist companies using aerial photogrammetry. The Department of Engineering of the States Board of Administration plan to follow Jersey in digitizing the large scale map archive. Development plans have been produced by the States of Guernsey Island Development Committee. Seven of these cover the island and show planning zones on a 1:5,000 scale OS base. A Guernsey leisure map at three inches to one mile was published in 1974 by BKS Surveys, derived from the earlier OS map at the same scale. It was in four colors with 25 ft contours, was on the Transverse Mercator projection with UTM grid and included an inset street map of St. Peter Port. The most recent general map of this island is in the military (M824 Series) and at the scale of 1:25,000. It was revised in 1985 and published in 1986 on a Transverse Mercator projection with UTM grid and has 10 m contours.
The smaller islands of the Channel Islands are all available as military edition maps published by Military Survey as part of the (M824 Series). Their scales and sheet dimensions vary, reflecting the differing sizes of the islands. Alderney is covered by a six inches to the mile (1:10,560) military map published in 1966. It is printed in three colors with 10 ft contour interval. The projection is Universal Transverse Mercator, as is the grid. This map was prepared and drawn by OS from 1:2,500 and 1:1,250 surveys made a decade earlier. OS revised the large scale mapping of Guernsey in 1987, and the whole island is available in 14 sheets at 1:2,500, while the town of St. Anne is covered by 1:1,250 scale mapping. A new colorful tourist map at 1:10,560 was published by OS for the States of Alderney in 1988. This is an enhanced and updated version of the military map, with the sea colored blue and the land area a pale green. The military map of Sark is also at six inches to the mile (1:10,560), and was published in 1965, having been compiled from air photography flown the previous year, and revised in 1992. This is a six-color map with UTM grid and latitude and longitude given at the corners of the sheet. The contour interval varies, being at 50 ft below 200 ft, 20 ft between 200 ft and 300 ft, and 10 ft thereafter. Herm and Jethou appear together on a single 1:10,000 sheet in the (M824) map series. This sheet was compiled from 1962 air photography and was published in 1969. Printing is in four colors, projection is UTM, with UTM grid, and there is a 5 m contour interval.
Geological mapping of the islands has been carried out by the British Geological Survey (BGS) including 1:25,000 scale coverage of Jersey and Guernsey published in the Classical areas of British geology series and hydrogeological mapping of Jersey at the same scale. The islands appear on nautical charts published by the British Hydrographic Office (HO).
The principal local commercial map and guide publisher in the Channel Islands is Perry’s Ltd. Perry’s guide map of Guernsey includes an extensive street index and appears in both book and sheet format. Perry’s produce tourist maps in various formats of Guernsey and also of the other Channel Islands, and their maps are revised every two years. The products are based on the official mapping and published as full-color mapping since 1995. The AA/Macmillan Channel islands traveller’s map is a full-color, double-sided map covering Guernsey, Jersey, Alderney, Sark, Herm and Jethou at scales at or close to 1:25,000. It also includes street maps of St. Peter Port and St. Helier, indices of streets, villages, hotels and places of interest on the larger islands and shows relief by layer coloring. In 1996 HarperCollins reissued its Bartholomew Channel Islands mapping as separate Holiday maps of Jersey and of Guernsey and the smaller islands, at a reduced scale, but to similar specifications to earlier Bartholomew maps. These also show relief with layer-coloring. A small scale tourist map of the islands is published by Geocenter in its Euro Tour map series.
In Jersey enumeration district mapping for the five-yearly census is prepared by the Department of Planning and Building Control, while in Guernsey the equivalent agency is the Economic and Statistics Division. Digital ED mapping was prepared for the latest census which was taken in 1996.