Two stealth nuclear submarines once bumped into each other by accident.
Late at night on February 3, 2009 in the Atlantic Ocean, two stealth-cloaked nuclear submarines (the Triomphant from France and HMS Vanguard from Britain) bumped into each other out of sheer coincidence. They were both cloaked so well from each other that neither submarine could detect the other, even when they were only a couple feet apart. Fortunately, no crew members were harmed in the accident but repairs were estimated to cost a minimum of 50 million dollars.
The Haus of Dcaligari 