The oceans are Earth's single most important feature. Explorer Paul Rose leads a team of ocean experts in a series of global science expeditions. With him, maritime archaeologist Dr Lucy Blue investigates our past and our relationship with the sea, exploring shipwrecks and lost civilisations; marine biologist and Oceanographer Tooni Mahto seeks the extraordinary life in our oceans today; and environmentalist Philippe Cousteau Jr looks to the future of our oceans and charts the way they're changing.