Ripple Rock () is an underwater mountain located in the Seymour Narrows of the Discovery Passage in British Columbia, Canada. It had two peaks (2.74 metres and 6.4 metres below the surface at low tide) that produced large, dangerous eddies from the strong tidal currents that flowed around them at low tide. Ships transiting the strait preferred to wait until slack tide in order to safely bypass the rock. The hazardous nature of the rock prompted the Canadian government to remove the top of the mountain in a controlled explosion on 5 April 1958. The event was one of the first live coast-to-coast television broadcasts of an event in Canada and was designated a National Historic Event of Canada. Etymology Ripple Rock was so named in 1862 by Captain Richards, RN, because its summits were about at sea level and made a prominent standing wave in the fast tidal current of the strait. History The rock was first noted by explorer George Vancouver in 1791, describing it as "one of the vilest stretches of water in the world". The first known large ship to fall prey to Ripple Rock was the sidewheel steamer Saranac in 1875, as it was heading north to Alaska. At least 20 large and 100 smaller vessels were badly damaged or sunk between then and 1958. At least 110 people drowned in these accidents. Early demolition proposals In the 1860s a plan was started to link Vancouver Island to the mainland at Bute Inlet, using Ripple Rock as a mid-support for the bridge. This plan continued through the years, and caused political opposition to destroying Ripple Rock, until it was decided to destroy the rock to improve safety for mariners. As early as 1931, a marine commission recommended removing Ripple Rock, but it was not until 1942 that the government authorized attempts to remove it and issued the first contract to do so. Early attempts The first attempts at planting explosive charges on Ripple Rock were made with floating drilling barges with the goal of blasting the rock into pieces. The first, in 1943, was secured with six 3.8 cm steel cables attached to anchors that altogether weighed 998 metric tons. This approach was abandoned when one cable broke on average every 48 hours. Another attempt in 1945, involving two large overhead steel lines was similarly abandoned after only 93 (out of 1,500 planned) controlled explosions