Engineers in British Columbia, Canada, detonated over 1,300 tons of Nitramex 2H explosive to vaporize Ripple Rock, an underwater mountain that had sunk over 100 vessels in the Seymour Narrows. The massive underwater blast was the largest non-nuclear planned explosion in history, requiring a complex network of vertical and horizontal shafts drilled from a nearby island. The explosion successfully restored safe navigation to the vital maritime transit route.

The televised blast was a major cultural milestone in Canada, inspiring modern poems that treated the event as a literal battle between human technology and primordial geographic barriers. It provided a powerful literary image of a hidden, underwater terror being instantly erased by science.