The Metrication of Admiralty Charts

Extract

By 1966 it was obvious, the Government having announced its intention for the country to go metric, that we had to think seriously of the metrication of Admiralty charts. With some 3500 navigational charts, many additional special charts, plotting sheets and other publications the task was unquestionably a formidable one, but it was decided that it could be done and a start should be made as early as possible.

It could be tackled in two ways, either by a gradual process, whereby charts would be converted as they came up for correction or where it was necessary to produce a new chart; this would mean slow progress and result in a haphazard geographical distribution. Alternatively such resources as were available could be concentrated in one area at a time and blocks of charts produced in metric units. This would avoid, to some extent, the difficulty to the mariner of having to jump about from fathoms and feet to metres and back again as he changed charts, and we eventually decided on this method—but in true British fashion are doing a bit of both.