Loss and discovery of the ferry Hydro – Lake Tinn

One of the most daring clandestine operations of World War II was the 1944 sinking of the Norwegian ferry Hydro, with its purported cargo of heavy water destined for the Nazis’ secret atomic bomb project. Heavy water is a form of water with a unique atomic structure and properties coveted for the production of nuclear power and weapons. Although the mission was declared a success, no one has established whether heavy water was actually on board. ProMare plunged 1,300 feet beneath a remote Norwegian lake to find the answer.

Exploring the bottom of Lake Tinn with a remotely operated vehicle, we located the well- preserved ship along with evidence of a mysterious cargo in steel drums. Analysis of the contents of one of those drums solved the longstanding mystery about the role that the Allies played in preventing a Nazi nuclear bomb. The cargo was indeed heavy water.

The tragic sinking of Hydro has inspired several films and books, especially because of the human sacrifice that was involved in the destruction of this potentially lethal to masses. Our projects in 2005 and 2017 were featured in two separate documentaries by NOVA and the National Geographic Channel. Please find the links to these two projects below.