S1, E101: This is a world you have never seen before – a world normally hidden under miles of water, the landscape of the ocean bed. The ocean is the last frontier and images of the deep are only glimpsed in the lights of a submarine or Remote Operated Vehicle, with most of this undersea world having never known the light of the sun. For the first time, combining the latest scientific data with state of the art CGI, this programme shows what it would look like if we were to drain the water from the oceans to reveal the mountains, canyons, plains and volcanoes that are more dramatic than anything on dry land. Leading scientists and institutes in the field of oceanography and marine science join in this quest to lay bare the landscapes of the deep and share their experiences and ideas about what this mysterious world might look like. Deep water corals that build mounds to rival the Miami skyline in size, a submerged canyon that is bigger than the Grand Canyon, a line of mountains that runs around the globe for 40,000 miles – all these features have only been known about for a few decades and while exploring these fascinating landscapes, scientists have discovered life forms that they had no idea existed – or could exist in these bizarre, hostile environments. This is a unique programme. One that combines the latest science with the most advanced film technology to recreate a world that exists under crushing depths of dark water, a world that no-one can ever see for themselves in such detail.