Remarkable means of transportation were used in 1976, when the flame was transformed to a radio signal and transmitted from Europe to the New World: Heat sensors in Athens detected the flame, the signal was sent to Ottawa via satellite where it was received and used to trigger a laser beam to re-light the flame. The torch, but not the flame, was taken into space by astronauts in 1996, 2000 and 2013. In 2000, the torch was carried under the water by divers near the Great Barrier Reef. Other unique means of transportation include a Native American canoe, a camel, and Concorde. The torch has been carried across water; the 1968 Grenoble Winter Games was carried across the port of Marseilles by a diver holding it aloft above the water. In 2000, an underwater flare was used by a diver across the Great Barrier Reef en route to the Sydney Games. In 2012 it was carried by boat across Bristol harbour in the UK and on the front of a London Underground train to Wimbledon.