In a flooded future Earth, people cling to manmade floating islands for survival. When a tyrannical madman (Dennis Hopper) driving a supertanker over the world in search of ‘dry land’ invades one of these islands, a mysterious wanderer named the ‘Mariner’ (Kevin Costner) rescues a woman and her adopted daughter from the slaughter and together they embark on a quest that could save mankind.

A fast-paced adventure set in a future time where Earth is covered in water and the human race struggles to survive in dilapidated boats and makeshift floating cities.