Looking at the phenomena of megawaves, with specialist jet-ski cameras riding the waves. Nazaré in Portugal is the site of the biggest ocean waves ever recorded on Earth. To understand the science behind these monsters, this stunning natural history documentary plunges beneath the waves to reveal the sprawling landscapes of the seabed. It also travels to South Africa and witnesses the Sardine Run, captures a circular rainbow at Victoria Falls and chases tornados in the Midwest.

The show’s own verdict is on its page.