South Sea Adventure / Volcano Adventure

Volcano Adventure – Hal and Roger Hunt are off to the Pacific to study volcanoes with scientist Dr Dan Adams. They share amazing experiences, but Dr Adams behaves strangely, and may be endangering them all.
South Sea Adventure – Hal and Roger are commissioned to bring back extraordinary sea creatures and visit remote pearl-oyster beds of a secret lagoon. Others are after the pearls too, and strand the boys on a desolate atoll.