Up until the start of the French-Indian war (1756-63) countries such as Britain, France and Spain were vying for control of overseas territories with little accurate information on the territories they were fighting over. As the war ensued it was becoming apparent to the British Government and military that accurate maps, plans and charts were going to be the way forward if success was to be enjoyed. This coincided with the rise of the engineer and draftsman training school at Woolwich in London.  
 
Directly after the end of the conflict enough had been accomplished to confirm the benefits of the work and two surveys of the continent were commissioned. Firstly, the General Survey of the lands of North America, under the respective auspices of the Lords of the Board of Trade.  The General Survey was to map British holdings in North America in respect of natural resources, especially forests, arable land, mining and ownership (government). The second survey of, under the auspices of the British Admiralty was commissioned to detailed hydrography and coastline in order to better preserve shipping, enable control of the coast and harbours and finally to identify deep water harbours suitable for naval/military ports.
 
To assist with the survey, in 1759, the British Admiralty issued instructions that all ships were required to make accurate observations as to the state of home and foreign coasts.  These observations were to include the sands, shoals, sea marks, soundings, bays and harbours, times of high water and setting of tides, and in particular directions for sailing into ports (or roads) and for avoiding dangers. This included anchorages, watering places, and descriptions for obtaining water, fuel, refreshment and provisions.  Any fortifications were to be noted and described in terms of form, strength and position.  Where artists were on-board ship, they should provide illustrations.
For further reading see the following:
EDELSTON, S. MAX. The New Map of Empire: How Britain Imagined America before Independence. Harvard University Press, 2017.
 
HORNSBY, STEPHEN J., and Hope Stege. Surveyors of Empire: Samuel Holland, J.F.W. Des Barres, and the Making of The Atlantic Neptune. McGill-Queen’s University Press, 2011.
Johnson, Alex. The First Mapping of America: The General Survey of British North America. United Kingdom: I.B.Tauris, 2017.

The British Survey of North America