Hundreds of thousands of tonnes of highly toxic materials lie scattered on ocean floors - in barrels that are rusting away and releasing their lethal contents. While we worry about weapons of mass destruction in the hands of rogue states, the West's legacy may prove far more dangerous. During the Second World War, Canada produced more chemical weapons than any other of the Allies. After the war, and during the Cold War era, massive weapons stockpiles were simply dumped into the ocean by the United States, Britain, Canada, the Soviet Union and Germany. They were considered buried and done with forever. Information about known dumps was either mishandled or suppressed. This documentary takes us on a journey to discover some of the most dangerous dump sites. The oceans are vast and finding weapons lying underwater will prove difficult. However, the health of marine species and coastal communities is at risk. Buried at Sea takes viewers on an underwater search and weaves the stories of people around the world whose lives have been affected by these chemical weapons.