25 Dollars - Elizabeth II 1768 Cook's Voyage of Discovery

Cook's first Pacific voyage aboard Endeavour departed Plymouth in August 1768, ostensibly to observe the transit of Venus from Tahiti — a Royal Society commission that gave the Admiralty plausible cover for the voyage's real strategic purpose: locating and charting the hypothetical southern continent. The astronomical observation was completed, but Terra Australis Incognita remained elusive. What Cook found instead was the eastern coastline of Australia and confirmed contact with New Zealand.

The Solomon Islands themselves had been visited by Europeans as early as 1568, two centuries before Cook, when Álvaro de Mendaña first charted them for Spain.