Made by Polytechnic Marine circa 1980-1981, the ‘Walker Marine Sat-Nav 802’ is an early example of a commercially available satellite navigation receiver used at sea. Previously only available to navies, technological breakthroughs in the production of microprocessors in the early 1980s made it possible to manufacture and sell satellite navigation receivers such as this one for marine markets including leisure, fishing and commercial.

The ‘Walker Marine Sat-Nav 802’ is a satellite navigation receiver that worked with the Transit satellite system to determine a user’s latitude and longitude. The Transit satellite system was developed by the United States Navy during the Cold War to provide accurate location information to Polaris submarines. The Transit satellite system became operational in 1964 and the technology was later made available for civilian use.

By the 1980s, navigators working on thousands of warships, freighters and private watercraft used the Transit system. This was partly due to changes in how consumer electronics were manufactured and advances in chip technology.
The ‘Walker Marine Sat-Nav 802’ was developed by a research and development team based in Daventry, UK and badged for sale by Walker. Walker was already a well-known supplier of equipment to the commercial maritime sector. The Walker Sat-Nav updated the firm’s technology into the satellite navigation era. The receiver has a similar internal system to the ‘Decca 801 SatNav’ (see ZBA9307) which was launched in January 1980.