Originally Posted by Geoff54
Sounds right to me. I think it's the only place that fits all the clues but I can't find it either.
Guadalcanal is the big island which was the scene of major fighting between the USA and Japan during the war. The land mass of Solomon Islands is 28,400 sq km (just under 30,000). So it should be somewhere to the east of the big island of Guadalcanal with it's capital of Honiara.
This is what the clues lead me to believe.