Detailed British Admiralty chart of the St Lawrence River. from Bic Island to Quebec.

The chart marks soundings, hazards of the sea, magnetic variation, lighthouses and beacons, with principal ports and rivers marked.

Captain Henry Wolsey Bayfield (1795-1885) was appointed admiralty survey for North America, June of 1817. He surveyed Lake Superior, Lake Erie and Lake Huron, among many others. fter several years surveying the lakes in North America, he returned to England in the autumn of 1825, and completed several charts of the lakes. He was promoted commander in 1826, and the following year, he travelled to Quebec to complete surveys of the St Lawrence River. He would hold the position until his retirement in 1866.

The British Hydrographic Office was founded in 1795 by George III, who appointed Alexander Dalrymple as the first Hydrographer to the Admiralty. The first charts were produced in 1800. Unlike the U. S. Coast Survey the Hydrographic Office was given permission to sell charts to the public and they produced a great number of sea charts covering every corner of the globe. Most of the Admiralty charts produced by the Hydrographic Office delineated coastline as well as high and low water marks and record depth of water as established by soundings. In addition these charts included information on shoals, reefs, and other navigational hazards that plagued mariners across the world. Thanks to the innovations of Sir Francis Beaufort, who developed the Beaufort Scale of wind strength, the British Hydrographic Office became one of the leading producers of sea charts. In fact, such was their accuracy that the phrase 'Safe as an Admiralty Chart' was coined.