Ripple Rock was an underwater, twin-peaked mountain in the Seymour Narrows of the Discovery Passage in British Columbia, Canada, a part of the marine trade route from Vancouver and coastal points north. The nearest town was Campbell River. Only 2.7 metres (9 feet) underwater at low tide, it was a marine hazard, described by the explorer George Vancouver as "one of vilest stretches of water in the world." It was destroyed by a planned explosion on April 5, 1958. This is a National Historic Event in Canada. The Ripple Rock explosion was seen throughout Canada, live on CBC Television. It was one of the first live coast to coast television coverages of an event in Canada.