Detailed chart of Saint-Augustin's Bay on the south west coast of Madagascar.

Aldrich's survey would supersede the work carried out by Captain William Fitzwilliam Owen, who had surveyed the east African coast and Madagascar in the 1820s.

Admiral Pelham Aldrich (1844-1930) was a Royal Navy officer and explorer, who became Admiral Superintendent of Portsmouth Docks. Aldrich joined the Royal Navy in 1859, and quickly rose through the ranks. In 1872, as first lieutenant, he served aboard HMS Callenger, whose famous voyage (1872-1876), made numerous scientific discoveries, and laid the foundations for the discipline of oceanography. In 1875, he joined the sloop Alert to take part in the British Arctic Expedition. In 1876, he was promoted to Commander and took charge of both HMS Sylvia and HMS Fawn, surveying parts of the Mediterrean, China, and Madagascar. It was whilst on Madagascar that Aldrich, along with the scientist Stephen Joseph Perry observed the transit of Venus.

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.