Eight young adventurers go to extremes to help the planet as they explore the world below the waves, snorkelling and diving in freezing sub-Antarctic waters. They also reach spectacular heights, climbing a mountain bordering the historic Magellan Strait to relive a key moment in its discovery by explorer Ferdinand Magellan in 1520.

The team continue to find life difficult aboard their yacht Valhalla, however, with arguments constantly flaring up. Show less