of oceanographic and naval meteorological data started. In the Second World War, while led by Vice-Admiral Sir John A. Edgell, chart printing moved to Creechbarrow House in Taunton in June 1941. This was the first purpose-built chart making factory, and was designed by the Chief Draughtsman, Mr Jowsey. In 1968, compilation staff were transferred from Cricklewood to Taunton, thus bringing together the main elements of the Hydrographic Office. A purpose-built office, named after Alexander Dalrymple, was opened. Metrication and computerisation of charts began in the later 1960s and early 1970s under the leadership of Rear-Admiral Sir Edmund G. Irving (1960–1966), Rear-Admiral George Stephen Ritchie (1966–1971), Rear-Admiral Geoffrey P. D. Hall (1971–1975) and Rear-Admiral Sir David W. Haslam (1975–1985). For centuries, data was mainly collected using ordinary Royal Navy ships. In 1953, the first purpose-built survey vessel was launched: . With the use of the echo sounder and other electronic equipment in the 20th century, there was a big increase in the quantity and quality of the data collected. The technology used to collect data also improved with the first commercial use of multibeam survey technology in 1977; undertook the first side-scan sonar of Mount's Bay, Cornwall, in 1987. The work has since been continued by the Bulldog-class survey vessels which form the "Hydrographic Squadron". In 1994, the Hydrographer of the Navy also became the Chief Executive of UKHO and the post was held by Rear-Admiral Nigel R. Essenhigh (1994–1996) and Rear-Admiral John P. Clarke (1996–2001). Publications The UKHO continues to serve the Royal Navy as its prime customer by supplying hydrographic and geospatial data. The UKHO's products and services are sold to merchant mariners and leisure users through its commercial portfolio of ADMIRALTY Maritime Data Solutions. In addition to traditional paper nautical charts and publications, the ADMIRALTY Maritime Data Solutions range has expanded to include a number of digital products and services. In 1996, the UKHO developed ADMIRALTY Raster Chart Service, a raster navigational chart service for Electronic Chart Display and Information System. This was followed in 2008 by ADMIRALTY Vector Chart Service, offering 15,750 fully vectorised Electronic Navigational Charts (ENCs). The UKHO produces over 200 nautical publications, which are available as e-Nautical Publications or in the Digital Publications suite. Notable publications include Sailing directions (Pilots), Tide tables, List of Radio Signals, List of Lights and Fog Signals and the Mariner’s Handbook. The UKHO also offers astronomical publications from HM