We have touched on English activity in the South Pacific in A Magnet for Ne'er-do-wells. George Anson (fn) continued that tradition when he set out from Portsmouth to attack Spanish colonies and ships off South America's Pacific coast in 1740.
(fn: George Anson (1697—1762) completed a remarkable circumnavigation (1740-44), capturing a Manila galleon along the way. As First Lord of the Admiralty, Anson instituted many significant reforms, removed corrupt defence contractors, improved medical care, and revised the Articles of War to tighten discipline. See here for a more detailed biographical sketch.)
The details of Anson's epic voyage form a significant part of English Approaches. His experiences prompted him, as First Lord of the Admiralty, to look for strategic assets on either side of the problematic passage around the bottom of South America.
The first attempt went out under John' Foulweather Jack' Byron, the grandfather of the noted poet Lord Byron. Byron left England in the frigate HMS Dolphin in June 1764; he was officially on his way to command the Royal Navy's East Indies Station. Although his secret orders contained an extensive itinerary, Byron managed to ignore almost all of it as he completed a twenty-two-month circumnavigation. It was the first such voyage completed in under two years.
Unfulfilled strategic imperatives saw the copper-bottomed Dolphin (fn) head out again almost immediately after Byron's return.
(fn: The Dolphin's copper sheathing
This time, the command went to a more junior officer, who was more likely to follow orders. Samuel Wallis (fn) had Philip Carteret in the almost-unseaworthy Swallow as an escort. The ships parted ways after a difficult passage through the Straits of Magellan. Both returned to England after carving substantial chunks off the part of the South Pacific where Terra Australis Incognita might lurk.
Most significantly, Wallis found Tahiti and arrived home in time to give James Cook an ideal location to observe the Transit of Venus.