The third and final episode in the Galapagos Islands features some of the "newer" islands, which are "only" a few hundred thousand years old. There are plenty of interesting creatures in the waters around these islands, like marine iguanas - the only known iguanas that swim in salt water and can stay underwater for more than an hour - and the Flightless Cormorant - a bird that uses its stubby wings to swim rather than fly. On Isabela Island, the crew visits Darwin's Lake - a saltwater lake - to study flower color and pollination and spends some time in Zodiac boats finding penguins endemic to the islands.