Guadalcanal

Guadalcanal is situated in the middle of the long Solomon Islands chain, north-east of Australia. The location of the Solomons made them a key to Japanese plans for cutting off shipping between the US and Australia. Japan held a major base on the northern end of the chain, at Rabaul, but the Solomons are so long that aircraft from Rabaul could not patrol the entirety of the island chain.

The Imperial Japanese Navy intended to turn the Solomons into a major strategic base, and in 1942 started a program of occupying islands all along the chain and building airbases for land-based patrol bombers. Guadalcanal was to be the major base in the middle of the chain, just within ferry range of Rabaul. If this had succeeded, Allied shipping would have been forced to take long detours to the south.

The Allies, aware of the Japanese plans, decided that Guadalcanal would serve just as well as a base for operations against Rabaul, so the US, Australian and New Zealand navies formed an invasion fleet.